CA1199997A — Control system, method of operating an electronic…

Claim 1

Independent Claim 150 words

A control system for an electronically commuta-ted DC motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, the control system comprising: means for controlling the application of a DC vol-tage to provide a resultant effective voltage to the winding stages, said controlling means including means for commutating the winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rota-table assembly; means for approximating a neutral conductor voltage for the DC motor; and means for comparing the approximated neutral conduc-tor voltage with the back emf of one of the winding stages, the output of said comparing means representing the angular position of the rotatable assembly; said controlling means being responsive to the out-put of said comparing means to cause said commutating means to commutate the winding stages when the rotatable assembly reaches a predetermined angular position.

Claim 2

Dependent Claim 150 words

A control system for an electronically commuta-ted DC motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, the control system comprising: means for controlling the application of a DC vol-tage to provide a resultant effective voltage to the winding stages, said controlling means including means for commutating the winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rota-table assembly; means for approximating a neutral conductor voltage for the DC motor; and means for comparing the approximated neutral conduc-tor voltage with the back emf of one of the winding stages, the output of said comparing means representing the angular position of the rotatable assembly; said controlling means being responsive to the out-put of said comparing means to cause said commutating means to commutate the winding stages when the rotatable assembly reaches a predetermined angular position.

Claim 3

Dependent Claim 74 words

The control system as set forth in claim 1 wherein the effective voltage is provided to less than all the winding stages at a time, the back emf for said comparing means being obtained from a winding stage not having the ef-fective voltage applied to it at that time, said approximating means including means for summing the terminal voltages of the winding stages to which the effective voltage is being pro-vided at that time.

Claim 4

Dependent Claim 66 words

The control system as set forth in claim 2 wherein the motor has three winding stages, the effective voltage being provided to only two of the stages at a time, the third stage providing the back emf for said comparing means, said approximating means including means for summing the terminal voltages of the two stages to which the effective voltage is being provided at that time.

Claim 5

Dependent Claim 44 words

The control system as set forth in claim 3 wherein said approximating means has one output for each pair of winding stages, the voltage on each output being a function of the sum of the terminal voltages of its associated pair of winding stages.

Claim 6

Dependent Claim 76 words

The control system as set forth in claim 4 fur-ther comprising electronically controlled switch means for connecting the outputs of the approximating means to one input of said comparing means, said electronically controlled switch means being responsive to said controlling means to connect said comparing means at a particular time only to that output of said approximating means associated with the pair of wind-ing stages to which the effective voltage is being provided at that time.

Claim 7

Dependent Claim 44 words

The control system as set forth in claim 2 wherein said approximating means has one output for each pair of winding stages, the voltage on each output being a function of the sum of the terminal voltages of its associated pair of winding stages.

Claim 8

Dependent Claim 76 words

The control system as set forth in claim 6 fur-ther comprising electronically controlled switch means for connecting the outputs of said approximating means to one in-put of said comparing means, said electronically controlled switch means being responsive to said controlling means to connect to said comparing means at a particular time only an output of said approximating means associated with a pair of winding stages to which the effective voltage is being pro-vided at that time.

Claim 9

Dependent Claim 108 words

The control system as set forth in claim 7 fur-ther comprising a set of back emf outputs, one for each wind-ing stage, the voltage on each back emf output being a func-tion of the terminal voltage of its associated winding stage at that particular time, and second electronically controlled switch means for connecting a second input of said comparing means to the back emf outputs, said electronically controlled switch means being responsive to said controlling means to connect said comparing means at a particular time only to a back emf output associated with a winding stage to which the effective voltage is not being provided at that time.

Claim 10

Dependent Claim 64 words

The control system as set forth in claim 8 wherein the DC motor has three winding stages, the effective voltage being provided to only two of the stages at a time, and said second electronically controlled switch means being responsive to said controlling means for connecting the second input of said comparing means to the back emf output associ-ated with the third winding stage.

Claim 11

Dependent Claim 167 words

A control system for an electronically commu-tated DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control sys-tem comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for approximating a neutral conductor voltage for the DC motor; means for comparing the approximated neutral conduc-tor voltage with the back emf of one of the winding stages, the output of said comparing means representing the angular position of the rotatable assembly; integrator means for integrating the output of said comparing means; second comparing means for generating a commutation signal when said integrator means output reaches a predeter-mined level; and decoding means responsive to the commutation signal for generating the set of control signals and providing the control signals to said commutating means to commutate the winding stages when the rotatable assembly reaches a predeter-mined angular position.

Claim 12

Dependent Claim 167 words

A control system for an electronically commu-tated DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control sys-tem comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for approximating a neutral conductor voltage for the DC motor; means for comparing the approximated neutral conduc-tor voltage with the back emf of one of the winding stages, the output of said comparing means representing the angular position of the rotatable assembly; integrator means for integrating the output of said comparing means; second comparing means for generating a commutation signal when said integrator means output reaches a predeter-mined level; and decoding means responsive to the commutation signal for generating the set of control signals and providing the control signals to said commutating means to commutate the winding stages when the rotatable assembly reaches a predeter-mined angular position.

Claim 13

Dependent Claim 32 words

The control system as set forth in claim 10 further comprising means for pulse width modulating the set of control signals, whereby a resultant effective voltage is pro-vided to the winding stages.

Claim 14

Dependent Claim 76 words

The control system as set forth in claim 11 wherein said controlling means provides the effective voltage to less than all the winding stages at a time, the back emf for said comparing means being obtained from a winding stage not having the effective voltage applied to it at that time, said approximating means including means for summing the term-inal voltages of the winding stages to which the effective voltage is being provided at that time.

Claim 15

Dependent Claim 71 words

The control system as set forth in claim 12 wherein the DC motor has three winding stages, the effective voltages being provided to only two of the winding stages at a time, the third winding stage providing the back emf signal for said comparing means, said approximating means including means for summing the terminal voltages of the two winding stages to which the effective voltage is being provided at that time.

Claim 16

Dependent Claim 44 words

The control system as set forth in claim 13 wherein said approximating means has one output for each pair of winding stases, the voltage on each output being a function of the sum of the terminal voltages of its associated pair of winding stages.

Claim 17

Dependent Claim 77 words

The control system as set forth in claim 14 further comprising electronically controlled switch means for connecting the outputs of said approximating means to the first comparing means, said electronically controlled switch means being responsive to said decoding means to connect an input of said comparing means at a particular time only to that output of said approximating means associated with the pair of winding stages to which the effective voltage is being provided at that time.

Claim 18

Dependent Claim 37 words

The control system as set forth in claim 10 further comprising delay means connected to said second com-paring means for digitally providing a delay signal for a pre-determined length of time in response to the commutation sig-nal.

Claim 19

Dependent Claim 222 words

A control system for an electronically commu-tated DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control sys-tem comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one winding stage; means for integrating a portion of the back emf sig-nal to produce an output indicative of the angular position of the rotatable assembly; first pulse generating means responsive to the out-put of said integrating means for generating a pulse when said integrator means output reaches a predetermined level; control signal means connected to the first pulse generating means for providing the set of control signals to said commutating means in response to receipt of a pulse to commutate the winding stages; and resettable digital timer means for providing a pulse to the control signal means to initiate rotation of the rotat-able assembly, said timer means providing the pulse to said control signal means unless said first pulse generating means generates a pulse before the expiration of a predetermined time interval, said timer means being reset by the pulse from said first pulse generating means.

Claim 20

Dependent Claim 222 words

A control system for an electronically commu-tated DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control sys-tem comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one winding stage; means for integrating a portion of the back emf sig-nal to produce an output indicative of the angular position of the rotatable assembly; first pulse generating means responsive to the out-put of said integrating means for generating a pulse when said integrator means output reaches a predetermined level; control signal means connected to the first pulse generating means for providing the set of control signals to said commutating means in response to receipt of a pulse to commutate the winding stages; and resettable digital timer means for providing a pulse to the control signal means to initiate rotation of the rotat-able assembly, said timer means providing the pulse to said control signal means unless said first pulse generating means generates a pulse before the expiration of a predetermined time interval, said timer means being reset by the pulse from said first pulse generating means.

Claim 21

Dependent Claim 38 words

The control system as set forth in claim 17 wherein said control signal means is preset to energize a par-ticular set of winding stases upon receipt of the pulse from said timer means to said control signal means.

Claim 22

Dependent Claim 206 words

A control system for an electronically commu-tated DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control sys-tem comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one winding stage; first pulse generating means responsive to the back emf signal for generating a pulse when the back emf signal in-dicates that a predetermined angular position of the rotatable assembly has been reached; control signal means connected to the first pulse generating means for providing the set of control signals to said commutating means in response to receipt of a pulse to commutate the winding stages; and resettable digital timer means for providing a pulse to the control signal means to initiate rotation of the rotat-able assembly, said timer means providing the pulse to said control signal means unless said first pulse generating means generates a pulse before the expiration of a predetermined time interval, said timer means being reset by the pulse from said first pulse generating means.

Claim 23

Dependent Claim 206 words

A control system for an electronically commu-tated DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control sys-tem comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one winding stage; first pulse generating means responsive to the back emf signal for generating a pulse when the back emf signal in-dicates that a predetermined angular position of the rotatable assembly has been reached; control signal means connected to the first pulse generating means for providing the set of control signals to said commutating means in response to receipt of a pulse to commutate the winding stages; and resettable digital timer means for providing a pulse to the control signal means to initiate rotation of the rotat-able assembly, said timer means providing the pulse to said control signal means unless said first pulse generating means generates a pulse before the expiration of a predetermined time interval, said timer means being reset by the pulse from said first pulse generating means.

Claim 24

Dependent Claim 38 words

The control system as set forth in claim 19 wherein said control signal means is preset to energize a par-ticular set of winding stages upon receipt of the pulse from said timer means to said control signal means.

Claim 25

Dependent Claim 176 words

A control system for an electronically commu-tated DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control sys-tem comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one winding stage; means responsive to the back emf signal for produc-ing a commutation signal indicative of a predetermined angular position of the rotatable assembly; and control signal means responsive to the commutation signal for providing the set of control signals to said commu-tating means to commutate the winding stages when the rotat-able assembly reaches the predetermined angular position; said control signal means including digital means for resetting said commutation signal producing means each time the winding stages are commutated, said digital resetting means including an electronically controlled switch responsive to the commutation pulse to reset said commutation signal pro-ducing means.

Claim 26

Dependent Claim 176 words

A control system for an electronically commu-tated DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control sys-tem comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one winding stage; means responsive to the back emf signal for produc-ing a commutation signal indicative of a predetermined angular position of the rotatable assembly; and control signal means responsive to the commutation signal for providing the set of control signals to said commu-tating means to commutate the winding stages when the rotat-able assembly reaches the predetermined angular position; said control signal means including digital means for resetting said commutation signal producing means each time the winding stages are commutated, said digital resetting means including an electronically controlled switch responsive to the commutation pulse to reset said commutation signal pro-ducing means.

Claim 27

Dependent Claim 53 words

The control system as set forth in claim 20 wherein said digital resetting means includes digital delay means for inhibiting the operation of said commutation signal producing means for a predetermined interval of time after the occurrence of the commutation pulse whereby commutation cur-rents are prevented from affecting said commutation signal producing means.

Claim 28

Dependent Claim 27 words

The control system as set forth in claim 22 wherein the predetermined interval of time corresponds to ap-proximately twenty electrical degrees of rotation of the ro-tatable assembly.

Claim 29

Dependent Claim 48 words

The control system as set forth in claim 21 further comprising means for approximating a neutral conductor voltage for said DC motor and wherein said back emf sensing means includes means for comparing the approximated neutral conductor voltage with the back emf of one of the winding stages.

Claim 30

Dependent Claim 25 words

The control system as set forth in claim 24 wherein said approximating means includes means for summing the terminal voltages of pairs of winding stages.

Claim 31

Dependent Claim 65 words

The control system as set forth in claim 21 further comprising resettable digital timer means for provid-ing a starting pulse to said control signal means to initiate rotation of the rotatable assembly, said timer means providing the pulse to said control signal means unless the commutation signal occurs before the expiration of a predetermined time interval, said timer means being reset by the commutation sig-nal.

Claim 32

Dependent Claim 33 words

The control system as set forth in claim 26 wherein said control signal means is preset to energize a par-ticular winding stage pair upon generation of the starting pulse by said timer means.

Claim 33

Dependent Claim 26 words

The control system as set forth in claim 21 wherein the commutation signal producing means comprises means for integrating a portion of the back emf signal.

Claim 34

Dependent Claim 49 words

The control system as set forth in claim 28 wherein the DC motor is a two-speed DC motor, said control system further including means responsive to a speed control signal for providing two different time constants for said in-tegrating means corresponding to the two speeds of the DC mo-tor.

Claim 35

Dependent Claim 34 words

The control system as set forth in claim 29 wherein said time constant providing means includes a pair of electronically controlled switches responsive to the commuta-tion signal to inhibit integration by said integrating means.

Claim 36

Dependent Claim 36 words

The control system as set forth in claim 29 wherein said time constant providing means includes a pair of electronically controlled switches and logic circuitry for preventing both switches from being closed at the same time.

Claim 37

Dependent Claim 79 words

The control system as set forth in claim 21 wherein said DC voltage applying means includes means for reg-ulating the magnitude of the applied DC voltage, said control system further including means for pulse width modulating the set of control signals, whereby a resultant effective voltage is provided to the winding stages, said voltage regulating means being responsive to an applied voltage above a prede-termined level to reduce the duty cycle of the pulses applied to the winding stages.

Claim 38

Dependent Claim 53 words

The control system as set forth in claim 21 further comprising means for inhibiting the control signal means to prevent the generation of the set of control signals when the motor current exceeds a predetermined maximum value, said inhibiting means maintaining the inhibition of said con-trol signal means until it is manually reset.

Claim 39

Dependent Claim 163 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, the control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing the angular position of the rotat-able assembly and for providing a commutation signal indica-tive of a predetermined angular position of the rotatable as-sembly; control signal means responsive to said position sensing and providing means for providing the set of control signals to said commutating means to commutate the winding stages when the rotatable assembly reaches the predetermined angular position; and means for inhibiting the control signal means to prevent the generation of the set of control signals when the motor current exceeds a predetermined maximum value, said in-hibiting means maintaining the inhibition of said control sig-nal means until it is manually reset.

Claim 40

Dependent Claim 163 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, the control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing the angular position of the rotat-able assembly and for providing a commutation signal indica-tive of a predetermined angular position of the rotatable as-sembly; control signal means responsive to said position sensing and providing means for providing the set of control signals to said commutating means to commutate the winding stages when the rotatable assembly reaches the predetermined angular position; and means for inhibiting the control signal means to prevent the generation of the set of control signals when the motor current exceeds a predetermined maximum value, said in-hibiting means maintaining the inhibition of said control sig-nal means until it is manually reset.

Claim 41

Dependent Claim 46 words

The control system as set forth in claim 34 wherein said inhibiting means includes means for temporarily inhibiting less than all the control signals when the motor current exceeds a second predetermined value, said second pre-determined current value being less than the predetermined maximum current value.

Claim 42

Dependent Claim 42 words

The control system as set forth in claim 35 wherein the DC motor has three winding stages, said control signal means including at least six logic gates, only three of which are inhibited when the motor current exceeds the second predetermined value.

Claim 43

Dependent Claim 45 words

The control system as set forth in claim 35 wherein the DC motor is a two-speed motor, said inhibiting means including means responsive to a speed control signal for providing two different predetermined second current values corresponding to the two speeds of the DC motor.

Claim 44

Dependent Claim 55 words

The control system as set forth in claim 35 further comprising means for sensing the voltage applied to the winding stages, said temporary inhibiting means being re-sponsive to an applied voltage exceeding a predetermined volt-age level to temporarily inhibit all the control signals but one to reduce the effective voltage applied to the winding stages.

Claim 45

Dependent Claim 69 words

The control system as set forth in claim 34 wherein the set of control signals are produced at the outputs of a set of logic gates and wherein said inhibiting means has an output for providing an inhibit signal when the predeter-mined maximum current value is exceeded, each of said logic gates having inputs connected to the inhibit signal output of said inhibiting means to receive the inhibit signal.

Claim 46

Dependent Claim 258 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least ore preselected sequence; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutatior, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; and means for pulse width modulating the control signal associated with the winding stage which was commutated on un-til a predetermined time after commutation and for shifting at that time to pulse width modulate the control signal associat-ed with the winding stage which will be deenergized after the next commutation.

Claim 47

Dependent Claim 258 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least ore preselected sequence; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutatior, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; and means for pulse width modulating the control signal associated with the winding stage which was commutated on un-til a predetermined time after commutation and for shifting at that time to pulse width modulate the control signal associat-ed with the winding stage which will be deenergized after the next commutation.

Claim 48

Dependent Claim 81 words

The control system as set forth in claim 40 wherein said commutating means includes first drive means as-sociated with each winding stage for allowing the flow of cur-rent through its associated winding stage in a first direction in response to a first one of the control signals and second drive means associated with each winding stage for allowing the flow of current through its associated winding stage in the opposite direction in response to a second one of the con-trol signals.

Claim 49

Dependent Claim 72 words

The control system as set forth in claim 41 further comprising means responsive to a signal indicative of motor current for inhibiting said logic means to prevent the generation of the set of control signals when the motor cur-rent exceeds a predetermined maximum value, thereby turning off said first and second drive means for all the winding stages, said inhibiting means preventing the generation of control signals until it is manually reset.

Claim 50

Dependent Claim 67 words

The control system as set forth in claim 42 where in said inhibiting means includes means for temporarily inhibiting all but one of the control signals when the motor current exceeds a second predetermined value, the second pre-determined current value being less than the predetermined maximum current value, whereby one of said first and second drive means is left on to allow circulation of the winding currents.

Claim 51

Dependent Claim 47 words

The control system as set forth in claim 43 wherein the DC motor is a two-speed motor, said inhibiting means including means responsive to a speed control signal and to an applied voltage exceeding a predetermined level to re-duce the effective voltage applied to the winding stages.

Claim 52

Dependent Claim 54 words

The control system as set forth in claim 43 further comprising means for sensing the voltage applied to the winding stages, said temporary inhibiting means being re-sponsive to an applied voltage exceeding a predetermined level to temporarily inhibit all the control signals but one to re-duce the effective voltage applied to the winding stages.

Claim 53

Dependent Claim 39 words

The control system as set forth in claim 41 wherein said pulse width modulating means includes means for modulating the control signals for said first drive means and the control signals for said second drive means substantially equal amounts.

Claim 54

Dependent Claim 113 words

The control system as set forth in claim 46 further comprising means for generating a drive selection sig-nal which changes state every commutation, said pulse width modulating means being responsive to a first state of the drive selection signal to shift from modulating the control signals for said first drive means to modulating the control signals for said second drive means upon the expiration of the predetermined time after commutation and being responsive to a second state of the drive selection signal to shift from modu-lating the control signals for said second drive means to mod-ulating the control signals for said first drive means upon the expiration of the predetermined time after commutation.

Claim 55

Dependent Claim 63 words

The control system as set forth in claim 40 further comprising means responsive to a signal indicative of motor current for inhibiting the logic means to prevent the generation of the set of control signals when the motor cur-rent exceeds a predetermined maximum value, thereby deenergiz-ing the winding stages, said inhibiting means preventing the generation of control signals until it is manually reset

Claim 56

Dependent Claim 63 words

The control system as set forth in claim 48 wherein said inhibiting means includes means for temporarily inhibiting all but one of the control signals when the motor current exceeds a second predetermined value, the second pre-determined current value being less than the predetermined maximum current value, whereby one of the winding stages is left on to allow circulation of the winding currents.

Claim 57

Dependent Claim 47 words

The control system as set forth in claim 49 wherein the DC motor is a two-speed motor, said inhibiting means including means responsive to a speed control signal and to an applied voltage exceeding a predetermined level to re-duce the effective voltage applied to the winding stages.

Claim 58

Dependent Claim 54 words

The control system as set forth in claim 49 further comprising means for sensing the voltage applied to the winding stages, said temporary inhibiting means being re-sponsive to an applied voltage exceeding a predetermined level to temporarily inhibit all the control signals but one to re-duce the effective voltage applied to the winding stages.

Claim 59

Dependent Claim 101 words

The control system as set forth in claim 40 further comprising means for sensing a back emf signal indica-tive of the back emf condition of at least one winding, means for integrating a portion of the back emf signal to produce an output indicative of the angular position of the rotatable as-sembly, and commutation signal generating means responsive to the output of said integrating means for generating a commuta-tion signal when said integrator means output reaches a pre-determined level, the commutation signal being the signal rep-resentative of the angular position of the rotatable assembly to which said logic means is responsive.

Claim 60

Dependent Claim 45 words

The control system as set forth in claim 52 further comprising digital means for resetting said integrat-ing means each time the winding stages are commutated, said digital resetting means including an electronically controlled switch responsive to the commutation signal to reset said in tegrating means.

Claim 61

Dependent Claim 84 words

The control system as set forth in claim 53 wherein said digital resetting means includes digital delay means for inhibiting the operation of said integrating means for the predetermined time after commutation, whereby commuta-tion currents are prevented from being integrated by said in-tegrating means, said pulse width modulating means being re-sponsive to said digital delay means to shift after the prede-termined time after commutation to pulse width modulate the control signal associated with the winding stage which will remain energized after the next commutation.

Claim 62

Dependent Claim 384 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least one preselected sequence, said commutating means includ-ing first drive means associated with each winding stage for allowing the flow of current through its associated winding stage in a first direction in response to a first one of the control signals and second drive means associated with each winding stage for allowing the flow of current through its as-sociated winding stage in the opposite direction in response to a second one of the control signals; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutation, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; means for generating a drive selection signal which changes state every commutation; and means responsive to a first state of the drive se-lection signal for shifting from pulse width modulating the control signals for said first drive means to pulse width mod-ulating the control signals for said second drive means upon the expiration of a predetermined time after commutation and responsive to a second state of the drive selection signal for shifting from pulse width modulating the control signals for said second drive means to pulse width modulating the control signals for said first drive means upon the expiration of the predetermined time after commutation

Claim 63

Dependent Claim 384 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least one preselected sequence, said commutating means includ-ing first drive means associated with each winding stage for allowing the flow of current through its associated winding stage in a first direction in response to a first one of the control signals and second drive means associated with each winding stage for allowing the flow of current through its as-sociated winding stage in the opposite direction in response to a second one of the control signals; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutation, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; means for generating a drive selection signal which changes state every commutation; and means responsive to a first state of the drive se-lection signal for shifting from pulse width modulating the control signals for said first drive means to pulse width mod-ulating the control signals for said second drive means upon the expiration of a predetermined time after commutation and responsive to a second state of the drive selection signal for shifting from pulse width modulating the control signals for said second drive means to pulse width modulating the control signals for said first drive means upon the expiration of the predetermined time after commutation

Claim 64

Dependent Claim 72 words

The control system as set forth in claim 55 further comprising means responsive to a signal indicative of motor current for inhibiting said logic means to prevent the generation of the set of control signals when the motor cur-rent exceeds a predetermined maximum value, thereby turning off said first and second drive means for all the winding stages, said inhibiting means preventing the generation of control signals until it is manually reset.

Claim 65

Dependent Claim 66 words

The control system as set forth in claim 56 wherein said inhibiting means includes means for temporarily inhibiting all but one of the control signals when the motor current exceeds a second predetermined value, the second pre-determined current value being less than the predetermined maximum current value, whereby one of said first and second drive means is left on to allow circulation of the winding currents.

Claim 66

Dependent Claim 47 words

The control system as set forth in claim 57 wherein the DC motor is a two-speed motor, said inhibiting means including means responsive to a speed control signal and to an applied voltage exceeding a predetermined level to re-duce the effective voltage applied to the winding stages.

Claim 67

Dependent Claim 54 words

The control system as set forth in claim 57 further comprising means for sensing the voltage applied to the winding stages, said temporary inhibiting means being re-sponsive to an applied voltage exceeding a predetermined level to temporarily inhibit all the control signals but one to re-duce the effective voltage applied to the winding stages.

Claim 68

Dependent Claim 101 words

The control system as set forth in claim 55 further comprising means for sensing a back emf signal indica-tive of the back emf condition of at least one winding, means for integrating a portion of the back emf signal to produce an output indicative of the angular position of the rotatable as-sembly, and commutation signal generating means responsive to the output of said integrating means for generating a commuta-tion signal when said integrator means output reaches a prede-termined level, the commutation signal being the signal repre-sentative of the angular position of the rotatable assembly to which said logic means is responsive.

Claim 69

Dependent Claim 44 words

The control system as set forth in claim 60 further comprising digital means for resetting said integrat-ing means each time the winding stages are commutated, said digital resetting means including an electronically controlled switch responsive to the commutation signal to reset said in-tegrating means.

Claim 70

Dependent Claim 84 words

The control system as set forth in claim 61 wherein said digital resetting means includes digital delay means for inhibiting the operation of said integrating means for the predetermined time after commutation, whereby commuta-tion currents are prevented from being integrated by said in-tegrating means, said pulse width modulating means being re-sponsive to said digital delay means to shift after the prede-termined time after commutation to pulse width modulate the control signal associated with the winding stage which will remain energized after the next commutation.

Claim 71

Dependent Claim 322 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least one preselected sequence; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutation, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; means for pulse width modulating the control sig-nals; and means responsive to a commutation selection signal for controlling said pulse width modulating means when the commutation selection signal is in a first state to pulse width modulate the control signal associated with the winding stage which is commutated on until a predetermined time after commutation and for shifting at that time to pulse width mod-ulate the control signal associated with the winding stage which will be deenergized after the next commutation and for controlling said pulse width modulating means when the commu-tation selection signal is in a second state to pulse width modulate the control signal associated with the winding stage which remained on.

Claim 72

Dependent Claim 322 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least one preselected sequence; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutation, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; means for pulse width modulating the control sig-nals; and means responsive to a commutation selection signal for controlling said pulse width modulating means when the commutation selection signal is in a first state to pulse width modulate the control signal associated with the winding stage which is commutated on until a predetermined time after commutation and for shifting at that time to pulse width mod-ulate the control signal associated with the winding stage which will be deenergized after the next commutation and for controlling said pulse width modulating means when the commu-tation selection signal is in a second state to pulse width modulate the control signal associated with the winding stage which remained on.

Claim 73

Dependent Claim 227 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least one preselected sequence; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutation, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; and means for pulse width modulating upon commutation the control signal associated with the winding stage which re-mained energized.

Claim 74

Dependent Claim 227 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least one preselected sequence; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutation, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; and means for pulse width modulating upon commutation the control signal associated with the winding stage which re-mained energized.

Claim 75

Dependent Claim 81 words

The control system as set forth in claim 64 wherein said commutating means includes first drive means as-sociated with each winding stage for allowing the flow of cur-rent through its associated winding stage in a first direction in response to a first one of the control signals and second drive means associated with each winding stage for allowing the flow of current through its associated winding stage in the opposite direction in response to a second one of the con-trol signals.

Claim 76

Dependent Claim 72 words

The control system as set forth in claim 65 further comprising means responsive to a signal indicative of motor current for inhibiting said logic means to prevent the generation of the set of control signals when the motor cur-rent exceeds a predetermined maximum value, thereby turning off said first and second drive means for all the winding stages, said inhibiting means preventing the generation of control signals until it is manually reset.

Claim 77

Dependent Claim 66 words

The control system as set forth in claim 66 wherein said inhibiting means includes means for temporarily inhibiting all but one of the control signals when the motor current exceeds a second predetermined value, the second pre-determined current value being less than the predetermined maximum current value, whereby one of said first and second drive means is left on to allow circulation of the winding currents.

Claim 78

Dependent Claim 47 words

The control system as set forth in claim 67 wherein the DC motor is a two-speed motor, said inhibiting means including means responsive to a speed control signal and to an applied voltage exceeding a predetermined level to re-duce the effective voltage applied to the winding stages.

Claim 79

Dependent Claim 54 words

The control system as set forth in claim 67 further comprising means for sensing the voltage applied to the winding stages, said temporary inhibiting means being re-sponsive to an applied voltage exceeding a predetermined level to temporarily inhibit all the control signals but one to re-duce the effective voltage applied to the winding stages.

Claim 80

Dependent Claim 97 words

The control system as set forth in claim 65 further comprising means for generating a drive selection sig-nal every other commutation, said pulse width modulating means being responsive to a first state of the drive selection sig-nal to shift from modulating the control signals for said first drive means to modulating the control signals for said second drive means upon commutation and being responsive to a second state of the drive selection signal to shift from modu-lating the control signals for said second drive means to mod-ulating the control signals for said first drive means upon commutation.

Claim 81

Dependent Claim 368 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least one preselected sequence, said commutating means includ-ing first drive menas associated with each winding stage for allowing the flow of current through its associated winding stage in a first direction in response to a first one of the control signals and second drive means associated with each winding stage for allowing the flow of current through its as-sociated winding stage in the opposite direction in response to a second one of the control signals; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutation, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; means for generating a drive selection signal every other commutation; and means responsive to a first state of the drive se-lection signal for shifting from pulse width modulating the control signals for said first drive means to pulse width mod-ulating the control signals for said second drive means upon commutation and responsive to a second state of the drive se-lection signal for shifting from pulse width modulating the control signals for said second drive means to pulse width modulating the control signals for said first drive means upon commutation.

Claim 82

Dependent Claim 368 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is ap-plied to pairs of other terminals of the winding stages in at least one preselected sequence, said commutating means includ-ing first drive menas associated with each winding stage for allowing the flow of current through its associated winding stage in a first direction in response to a first one of the control signals and second drive means associated with each winding stage for allowing the flow of current through its as-sociated winding stage in the opposite direction in response to a second one of the control signals; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in a sequence in which for each commutation one of the winding stages which was energized before commutation remains energized after commuta-tion and the other winding stage which was energized before commutation becomes deenergized after commutation, each wind-ing stage remaining energized through two successive commuta-tions unique to it and then becoming deenergized, the direc-tion of current flow in the winding stage which remains ener-gized after commutation being the same as the direction of current flow in that winding stage before commutation; means for generating a drive selection signal every other commutation; and means responsive to a first state of the drive se-lection signal for shifting from pulse width modulating the control signals for said first drive means to pulse width mod-ulating the control signals for said second drive means upon commutation and responsive to a second state of the drive se-lection signal for shifting from pulse width modulating the control signals for said second drive means to pulse width modulating the control signals for said first drive means upon commutation.

Claim 83

Dependent Claim 72 words

The control system as set forth in claim 71 further comprising means responsive to a signal indicative of motor current for inhibiting said logic means to prevent the generation of the set of control signals when the motor cur-rent exceeds a predetermined maximum value, thereby turning off said first and second drive means for all the winding stages, said inhibiting means preventing the generation of control signals until it is manually reset.

Claim 84

Dependent Claim 66 words

The control system as set forth in claim 72 wherein said inhibiting means includes means for temporarily inhibiting all but one of the control signals when the motor current exceeds a second predetermined value, the second pre-determined current value being less than the predetermined maximum current value, whereby one of said first and second drive means is left on to allow circulation of the winding currents.

Claim 85

Dependent Claim 47 words

The control system as set forth in claim 73 wherein the DC motor is a two-speed motor, said inhibiting means including means responsive to a speed control signal and to an applied voltage exceeding a predetermined level to re-duce the effective voltage applied to the winding stages.

Claim 86

Dependent Claim 54 words

The control system as set forth in claim 73 further comprising means for sensing the voltage applied to the winding stages, said temporary inhibiting means being re-sponsive to an applied voltage exceeding a predetermined level to temporarily inhibit all the control signals but one to re-duce the effective voltage applied to the winding stages.

Claim 87

Dependent Claim 237 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in a first sequence to cause rotation of the rotatable as-sembly in a first direction and for commutating the winding stages by applying the DC voltage thereto in a second sequence to cause rotation of the rotatable assembly in a second direc-tion opposite the first direction; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in the first and second sequences, said logic means also being responsive to a direction signal to supply the control signals in the first sequence when the state of the direction signal represents de-sired rotation in the first direction and to supply the con-trol signals in the second sequence when the state of the di-rection signal represents desired rotation in the second direction; and means responsive to a change in the state of the direction signal to delay said logic means from switching from one of the first and second sequences to the other thereof as required by the new state of the direction signal until the expiration of a predetermined delay time after the change in state of the direction signal.

Claim 88

Dependent Claim 237 words

A control system for an electronically commu-tated motor having a rotatable assembly and a stationary as-sembly with a plurality of winding stages, said control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in a first sequence to cause rotation of the rotatable as-sembly in a first direction and for commutating the winding stages by applying the DC voltage thereto in a second sequence to cause rotation of the rotatable assembly in a second direc-tion opposite the first direction; logic means responsive to a signal representative of the angular position of the rotatable assembly for supplying the control signals to said commutating means in the first and second sequences, said logic means also being responsive to a direction signal to supply the control signals in the first sequence when the state of the direction signal represents de-sired rotation in the first direction and to supply the con-trol signals in the second sequence when the state of the di-rection signal represents desired rotation in the second direction; and means responsive to a change in the state of the direction signal to delay said logic means from switching from one of the first and second sequences to the other thereof as required by the new state of the direction signal until the expiration of a predetermined delay time after the change in state of the direction signal.

Claim 89

Dependent Claim 49 words

The control system as set forth in claim 76 further comprising means for pulse width modulating the con-trol signals, said delay means being responsive to the pulse width modulating means to provide a predetermined delay time equivalent to at least for one pulse from said pulse width modulating means.

Claim 90

Dependent Claim 20 words

The control system as set forth in claim 77 wherein said pulse width modulating means has a fixed pulse frequency.

Claim 91

Dependent Claim 164 words

A control system for an electronically commu-tated, two-speed DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one winding; means for integrating a portion of the back emf sig-nal and for producing a commutation signal indicative of a predetermined angular position of the rotatable assembly; control signal means responsive to the commutation signal for providing the set of control signals to said com-mutating means to commutate the winding stages when the rotat-able assembly reaches the predetermined angular position; and means responsive to a speed control signal for pro-viding two different time constants for said integrating means corresponding to the two speeds of the DC motor.

Claim 92

Dependent Claim 164 words

A control system for an electronically commu-tated, two-speed DC motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the control system comprising: means responsive to a set of control signals for commutating the winding stages by applying a DC voltage there-to in at least one preselected sequence to cause rotation of the rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one winding; means for integrating a portion of the back emf sig-nal and for producing a commutation signal indicative of a predetermined angular position of the rotatable assembly; control signal means responsive to the commutation signal for providing the set of control signals to said com-mutating means to commutate the winding stages when the rotat-able assembly reaches the predetermined angular position; and means responsive to a speed control signal for pro-viding two different time constants for said integrating means corresponding to the two speeds of the DC motor.

Claim 93

Dependent Claim 47 words

The control system as set forth in claim 79 further comprising digital delay means for inhibiting the op-eration of said integrating means for a predetermined interval of time after the occurrence of the commutation signal whereby commutation currents are prevented from being integrated by said integrating means.

Claim 94

Dependent Claim 48 words

The control system as set forth in claim 79 further comprising means for approximating a neutral conductor voltage for the DC motor and wherein said back emf sensing means includes means for comparing the approximated neutral conductor voltage with the back emf of one of the winding stages.

Claim 95

Dependent Claim 34 words

The control system as set forth in claim 79 wherein said time constant providing means includes a pair of electronically controlled switches responsive to the commuta-tion signal to inhibit integration by said integrating means.

Claim 96

Dependent Claim 36 words

The control system as set forth in claim 79 wherein said time constant providing means includes a pair of electronically controlled switches and logic circuitry for preventing both switches from being closed at the same time

Claim 97

Dependent Claim 193 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means for controlling the application of the DC voltage to provide a resultant ef-fective voltage to said winding stages, said controlling means including means for commutating said winding stages by apply-ing the DC voltage thereto in at least one preselected se-quence to cause rotation of said rotatable assembly means, thereby to cause rotation of said rotatable component; means for approximating a neutral conductor voltage for said DC motor; and means for comparing the approximated neutral conduc-tor voltage with the back emf of one of said winding stages, the output of said comparing means representing the angular position of said rotatable assembly means; said controlling means further including means re-sponsive to the output of said comparing means to cause said commutating means to commutate said winding stages when said rotatable assembly means reaches a predetermined angular posi-tion.

Claim 98

Dependent Claim 193 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means for controlling the application of the DC voltage to provide a resultant ef-fective voltage to said winding stages, said controlling means including means for commutating said winding stages by apply-ing the DC voltage thereto in at least one preselected se-quence to cause rotation of said rotatable assembly means, thereby to cause rotation of said rotatable component; means for approximating a neutral conductor voltage for said DC motor; and means for comparing the approximated neutral conduc-tor voltage with the back emf of one of said winding stages, the output of said comparing means representing the angular position of said rotatable assembly means; said controlling means further including means re-sponsive to the output of said comparing means to cause said commutating means to commutate said winding stages when said rotatable assembly means reaches a predetermined angular posi-tion.

Claim 99

Dependent Claim 73 words

The laundering apparatus as set forth in claim 84 wherein said DC motor has three winding stages, said con-trolling means providing the effective voltage to only two of said winding stages at a time, said third stage providing the back emf signal for said comparing means, and said approximat-ing means including means for summing the terminal voltages of said two winding stages to which the effective voltage is be-ing provided at that time.

Claim 100

Dependent Claim 73 words

The laundering apparatus as set forth in claim 85 further comprising electronically controlled switch means for connecting the outputs of said approximating means to said comparing means, said electronically controlled switch means being responsive to said controlling means to connect said comparing means at a particular time only to that output of the approximating means associated with said pair of winding stages to which the effective voltage is being provided at that time.

Claim 101

Dependent Claim 208 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly means, thereby to cause rotation of said rotatable component; means for approximating a neutral conductor voltage for said DC motor; means for comparing the approximated neutral conduc-tor voltage with the back emf of one of said winding stages, the output of said comparing means representing the angular position of said rotatable assembly means; integrator means for integrating the output of said comparing means; second comparing means for generating a commutation signal when said integrator means output reaches a predeter-mined level; and decoding means responsive to the commutation signal for generating the set of control signals and providing the control signals to said commutating means to commutate said winding stages when said rotatable assembly means reaches a predetermined angular position.

Claim 102

Dependent Claim 208 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly means, thereby to cause rotation of said rotatable component; means for approximating a neutral conductor voltage for said DC motor; means for comparing the approximated neutral conduc-tor voltage with the back emf of one of said winding stages, the output of said comparing means representing the angular position of said rotatable assembly means; integrator means for integrating the output of said comparing means; second comparing means for generating a commutation signal when said integrator means output reaches a predeter-mined level; and decoding means responsive to the commutation signal for generating the set of control signals and providing the control signals to said commutating means to commutate said winding stages when said rotatable assembly means reaches a predetermined angular position.

Claim 103

Dependent Claim 32 words

The laundering apparatus as set forth in claim 87 further comprising means for pulse width modulating the set of control signals, whereby a resultant effective voltage is provided to said winding stages.

Claim 104

Dependent Claim 42 words

The laundering apparatus as set forth in claim 87 further comprising delay means connected between said sec-ond comparing means and said decoding means for delaying the action of said decoding means a predetermined length of time in response to the commutation signal.

Claim 105

Dependent Claim 257 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly means; means for sensing a back emf signal indicative of the back emf condition of at least one of said winding stages; means for integrating a portion of the back emf sig-nal to produce an output indicative of the angular position of said rotatable assembly means; first pulse generating means responsive to the out-put of said integrating means for generating a pulse when said integrator means output reaches a predetermined level; control signal means connected to said first pulse generating means for providing the set of control signals to said commutating means in response to receipt of a pulse to commutate said winding stages; and resettable digital timer means for providing a pulse to said control signal means to initiate rotation of said ro-tatable assembly means, said timer means providing the pulse to said control signal means unless said first pulse generat-ing means generates a pulse before the expiration of a prede-termined time interval, said timer means being reset by the pulse from said first pulse generating means.

Claim 106

Dependent Claim 257 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly means; means for sensing a back emf signal indicative of the back emf condition of at least one of said winding stages; means for integrating a portion of the back emf sig-nal to produce an output indicative of the angular position of said rotatable assembly means; first pulse generating means responsive to the out-put of said integrating means for generating a pulse when said integrator means output reaches a predetermined level; control signal means connected to said first pulse generating means for providing the set of control signals to said commutating means in response to receipt of a pulse to commutate said winding stages; and resettable digital timer means for providing a pulse to said control signal means to initiate rotation of said ro-tatable assembly means, said timer means providing the pulse to said control signal means unless said first pulse generat-ing means generates a pulse before the expiration of a prede-termined time interval, said timer means being reset by the pulse from said first pulse generating means.

Claim 107

Dependent Claim 42 words

The laundering apparatus as set forth in claim 90 wherein said control signal means includes decoding means which are preset to energize a particular winding stage pair upon the providing of the pulse from said timer means to said control signal means.

Claim 108

Dependent Claim 290 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated motor, said motor com-prising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for supplying a DC voltage to said control system; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly means, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is applied to pairs of other terminals of said winding stages in at least one preselected sequence; logic means responsive to a signal representative of the angular position of said rotatable assembly means for sup-plying the control signals to said commutating means in a se-quence in which for each commutation one of said winding stages which was energized before commutation remains ener-gized after commutation and another winding stage which was energized before commutation becomes deenergized after commu-tation, each winding stage remaining energized through two successive commutations unique to it and then becoming deener-gized, the direction of current flow in said winding stage which remains energized after commutation being the same as the direction of current flow in that winding stage before commutation; and means for pulse width modulating the control signal associated with said winding stage which remains on after com-mutation until a predetermined time after commutation and for shifting at that time to pulse width modulate the control sig-nal associated with said winding stage which will remain on after the next commutation.

Claim 109

Dependent Claim 290 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated motor, said motor com-prising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for supplying a DC voltage to said control system; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly means, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is applied to pairs of other terminals of said winding stages in at least one preselected sequence; logic means responsive to a signal representative of the angular position of said rotatable assembly means for sup-plying the control signals to said commutating means in a se-quence in which for each commutation one of said winding stages which was energized before commutation remains ener-gized after commutation and another winding stage which was energized before commutation becomes deenergized after commu-tation, each winding stage remaining energized through two successive commutations unique to it and then becoming deener-gized, the direction of current flow in said winding stage which remains energized after commutation being the same as the direction of current flow in that winding stage before commutation; and means for pulse width modulating the control signal associated with said winding stage which remains on after com-mutation until a predetermined time after commutation and for shifting at that time to pulse width modulate the control sig-nal associated with said winding stage which will remain on after the next commutation.

Claim 110

Dependent Claim 81 words

The laundering apparatus as set forth in claim 92 wherein said commutating means includes first drive means associated with each winding stage for allowing the flow of current through its associated winding stage in a first direc-tion in response to a first one of the control signals and second drive means associated with each winding stage for al-lowing the flow of current through its associated winding stage in the opposite direction in response to a second one of the control signals.

Claim 111

Dependent Claim 72 words

The laundering apparatus as set forth in claim 93 further comprising means responsive to a signal indicative of motor current for inhibiting said logic means to prevent the generation of the set of control signals when the motor current exceeds a predetermined maximum value, thereby turning off said first and second drive means for all said winding stages, said inhibiting means preventing the generation of control signals until it is manually reset.

Claim 112

Dependent Claim 66 words

The laundering apparatus as set forth in claim 94 wherein said inhibiting means includes means for temporari-ly inhibiting all but one of the control signals when the mo-tor current exceeds a second predetermined value, the second predetermined current value being less than the predetermined maximum current value, whereby one of said first and second drive means is left on to allow circulation of the winding currents.

Claim 113

Dependent Claim 45 words

The laundering apparatus as set forth in claim 95 wherein said DC motor is a two-speed motor, said inhibiting means including means responsive to a speed control signal for providing two different predetermined second current values corresponding to the two speeds of said DC motor.

Claim 114

Dependent Claim 54 words

The laundering apparatus as set forth in claim 95 further comprising means for sensing the voltage applied to said winding stages, said temporary inhibiting means being re-sponsive to an applied voltage exceeding a predetermined level to temporarily inhibit all the control signals but one to re-duce the effective voltage applied to said winding stages.

Claim 115

Dependent Claim 39 words

The laundering apparatus as set forth in claim 93 wherein said pulse width modulating means includes means for modulating the control signals for said first drive means and the control signals for said second drive means substan-tially equal amounts.

Claim 116

Dependent Claim 111 words

The laundering apparatus as set forth in claim 98 further comprising means for generating a drive selection signal every other commutation, said pulse width modulating means being responsive to a first state of the drive selection signal to shift from modulating the control signals for said first drive means to modulating the control signals for said second drive means upon the expiration of the predetermined time after commutation and being responsive to a second state of the drive selection signal to shift from modulating the control signals for said second drive means to modulating the control signals for said first drive means upon the expiration of the predetermined time after commutation.

Claim 117

Dependent Claim 102 words

The laundering apparatus as set forth in claim 92 further comprising means for sensing a back emf signal in-dicative of the back emf condition of at least one winding stage, means for integrating a portion of the back emf signal to produce an output indicative of the angular position of said rotatable assembly means, and pulse generating means re-sponsive to the output of said integrating means for generat-ing a commutation pulse when said integrator means output reaches a predetermined level, the pulse being the signal rep-resentative of the angular position of said rotatable assembly means to which said logic means is responsive.

Claim 118

Dependent Claim 44 words

The laundering apparatus as set forth in claim 100 further comprising digital means for resetting said inte-grating means each time said winding stages are commutated, said digital resetting means including an electronically con-trolled switch responsive to the commutation pulse to reset said integrating means.

Claim 119

Dependent Claim 84 words

The laundering apparatus as set forth in claim 101 wherein said digital resetting means includes digital de-lay means for inhibiting the operation of said integrating means for the predetermined time after commutation, whereby commutation currents are prevented from being integrated by said integrating means, said pulse width modulating means be-ing responsive to said digital delay means to shift after the predetermined time after commutation to pulse width modulate the control signal associated with said winding stage which will remain on after the next commutation.

Claim 120

Dependent Claim 49 words

The laundering apparatus as set forth in claim 101 wherein said DC motor is a two-speed DC motor, said con-trol system further including means responsive to a speed con-trol signal for providing two different time constants for said integrating means corresponding to the two speeds of said DC motor.

Claim 121

Dependent Claim 240 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one of said winding stages; first pulse generating means responsive to the back emf signal for generating a pulse when the back emf signal in-dicates that a predetermined angular position of the rotatable assembly means has been reached; control signal means connected to said first pulse generating means for providing the set of control signals to said commutating means in response to receipt of a pulse to commutate said winding stages; and resettable digital timer means for providing a pulse to said control signal means to initiate rotation of said ro-tatable assembly means, said timer means providing the pulse to said control signal means unless said first pulse generat-ing means generates a pulse before the expiration of a prede-termined time interval, said timer means being reset by the pulse from said first pulse generating means.

Claim 122

Dependent Claim 240 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly; means for sensing a back emf signal indicative of the back emf condition of at least one of said winding stages; first pulse generating means responsive to the back emf signal for generating a pulse when the back emf signal in-dicates that a predetermined angular position of the rotatable assembly means has been reached; control signal means connected to said first pulse generating means for providing the set of control signals to said commutating means in response to receipt of a pulse to commutate said winding stages; and resettable digital timer means for providing a pulse to said control signal means to initiate rotation of said ro-tatable assembly means, said timer means providing the pulse to said control signal means unless said first pulse generat-ing means generates a pulse before the expiration of a prede-termined time interval, said timer means being reset by the pulse from said first pulse generating means.

Claim 123

Dependent Claim 42 words

The laundering apparatus as set forth in claim 104 wherein said control signal means includes decoding means which are preset to energize a particular winding stage pair upon the providing of the pulse from said timer means to said control signal means.

Claim 124

Dependent Claim 413 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated motor, said motor com-prising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor, and means for supplying a DC voltage to said control system; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly means, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is applied to pairs of other terminals of said winding stages in at least one preselected sequence, said commutating means including first drive means associated with each winding stage for allowing the flow of current through its associated winding stage in a first direc-tion in response to a first one of the control signals and second drive means associated with each winding stage for al-lowing the flow of current through its associated winding stage in the opposite direction in response to a second one of the control signals; logic means responsive to a signal representative of the angular position of said rotatable assembly means for sup-plying the control signals to said commutating means in a se-quence in which for each commutation one of said winding stages which was energized before commutation remains ener-gized after commutation and another winding stage which was energized before commutation becomes deenergized after commu-tation, each winding stage remaining energized through two successive commutations unique to it and then becoming deener-gized, the direction of current flow in said winding stage which remains energized after commutation being the same as the direction of current flow in that winding stage before commutation; means for generating a drive selection signal every other commutation; and means responsive to a first state of the drive se-lection signal for shifting from pulse width modulating the control signals for the first drive means to pulse width modu-lating the control signals for the second drive means upon the expiration of a predetermined time after commutation and re-sponsive to a second state of the drive selection signal for shifting from pulse width modulating the control signals for the second drive means to pulse width modulating the control signals for the first drive means upon the expiration of the predetermined time after commutation.

Claim 125

Dependent Claim 413 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated motor, said motor com-prising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor, and means for supplying a DC voltage to said control system; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of said rotatable assembly means, each winding stage having at least two terminals, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is applied to pairs of other terminals of said winding stages in at least one preselected sequence, said commutating means including first drive means associated with each winding stage for allowing the flow of current through its associated winding stage in a first direc-tion in response to a first one of the control signals and second drive means associated with each winding stage for al-lowing the flow of current through its associated winding stage in the opposite direction in response to a second one of the control signals; logic means responsive to a signal representative of the angular position of said rotatable assembly means for sup-plying the control signals to said commutating means in a se-quence in which for each commutation one of said winding stages which was energized before commutation remains ener-gized after commutation and another winding stage which was energized before commutation becomes deenergized after commu-tation, each winding stage remaining energized through two successive commutations unique to it and then becoming deener-gized, the direction of current flow in said winding stage which remains energized after commutation being the same as the direction of current flow in that winding stage before commutation; means for generating a drive selection signal every other commutation; and means responsive to a first state of the drive se-lection signal for shifting from pulse width modulating the control signals for the first drive means to pulse width modu-lating the control signals for the second drive means upon the expiration of a predetermined time after commutation and re-sponsive to a second state of the drive selection signal for shifting from pulse width modulating the control signals for the second drive means to pulse width modulating the control signals for the first drive means upon the expiration of the predetermined time after commutation.

Claim 126

Dependent Claim 72 words

The laundering apparatus as set forth in claim 106 further comprising means responsive to a signal indicative of motor current for inhibiting said logic means to prevent the generation of the set of control signals when the motor current exceeds a predetermined maximum value, thereby turning off said first and second drive means for all said winding stages, said inhibiting means preventing the generation of control signals until it is manually reset.

Claim 127

Dependent Claim 66 words

The laundering apparatus as set forth 107 wherein said inhibiting means. includes means for temporar-ily inhibiting all but one of the control signals when the mo- . tor current exceeds a second predetermined value, the second predetermined current value being less than the predetermined maximum current value, whereby one of said first and second drive means is left on to allow circulation of the winding currents.

Claim 128

Dependent Claim 66 words

The laundering apparatus as set forth 107 wherein said inhibiting means. includes means for temporar-ily inhibiting all but one of the control signals when the mo- . tor current exceeds a second predetermined value, the second predetermined current value being less than the predetermined maximum current value, whereby one of said first and second drive means is left on to allow circulation of the winding currents.

Claim 129

Dependent Claim 45 words

The laundering apparatus as set forth in claim 108 wherein said DC motor is a two-speed motor, said inhibit-ing means including means responsive to a speed control signal for providing two different predetermined second current val-ues corresponding to the two speeds of said DC motor.

Claim 130

Dependent Claim 54 words

The laundering apparatus as set forth in claim 108 further comprising means for sensing the voltage applied to said winding stages, said temporary inhibiting means being responsive to an applied voltage exceeding a predetermined level to temporarily inhibit all the control signals but one to reduce the effective voltage applied to said winding stages.

Claim 131

Dependent Claim 102 words

The laundering apparatus as set forth in claim 106 further comprising means for sensing a back emf signal in-dicative of the back emf condition of at least one winding stage, means for integrating a portion of the back emf signal to produce an output indicative of the angular position of said rotatable assembly means, and pulse generating means re-sponsive to the output of said integrating means for generat-ing a commutation pulse when said integrator means output reaches a predetermined level, the pulse being the signal rep-resentative of the angular position of said rotatable assembly means to which said logic means is responsive.

Claim 132

Dependent Claim 44 words

The laundering apparatus as set forth in claim 111 further comprising digital means for resetting said inte-grating means each time said winding stages are commutated, said digital resetting means including an electronically con-trolled switch responsive to the commutation pulse to reset said integrating means.

Claim 133

Dependent Claim 84 words

The laundering apparatus as set forth in claim 112 wherein said digital resetting means includes digital de-lay means for inhibiting the operation of said integrating means for the predetermined time after commutation, whereby commutation currents are prevented from being integrated by said integrating means, said pulse width modulating means be-ing responsive to said digital delay means to shift after the predetermined time after commutation to pulse width modulate the control signal associated with said winding stage which will remain on after the next commutation.

Claim 134

Dependent Claim 49 words

The laundering apparatus as set forth in claim 112 wherein said DC motor is a two-speed DC motor, said con-trol system further including means responsive to a speed con-trol signal for providing two different time constants for said integrating means corresponding to the two speeds of said DC motor.

Claim 135

Dependent Claim 263 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for supplying a DC voltage to said control system; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in a first preselected se-quence to cause rotation of the rotatable assembly means in a first direction and for commutating the winding stages by ap-plying the DC voltage thereto in a second preselected sequence to cause rotation of the rotatable assembly means in a second direction, logic means responsive to a signal representative of the angular position of said rotatable assembly means for sup-plying the control signals to the commutating means in the first and second sequences, said logic means also being re-sponsive to a direction signal to supply the control signals in the first sequence when the direction signal represents de-sired rotation in the first direction and to supply the con-trol signals in the second sequence when the direction signal represents desired rotation in the second direction; and means responsive to a change in the state of the di-rection signal to delay said logic means from switching from one of the first and second sequences to the other thereof as required by the new state of the direction signal until the expiration of a predetermined delay time after the change in state of the direction signal.

Claim 136

Dependent Claim 263 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of wind-ing stages; a control system connected to said motor; and means for supplying a DC voltage to said control system; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in a first preselected se-quence to cause rotation of the rotatable assembly means in a first direction and for commutating the winding stages by ap-plying the DC voltage thereto in a second preselected sequence to cause rotation of the rotatable assembly means in a second direction, logic means responsive to a signal representative of the angular position of said rotatable assembly means for sup-plying the control signals to the commutating means in the first and second sequences, said logic means also being re-sponsive to a direction signal to supply the control signals in the first sequence when the direction signal represents de-sired rotation in the first direction and to supply the con-trol signals in the second sequence when the direction signal represents desired rotation in the second direction; and means responsive to a change in the state of the di-rection signal to delay said logic means from switching from one of the first and second sequences to the other thereof as required by the new state of the direction signal until the expiration of a predetermined delay time after the change in state of the direction signal.

Claim 137

Dependent Claim 48 words

The laundering apparatus as set forth in claim 115 further including means for pulse width modulating the control signals, said delay means being responsive to said pulse width modulating means to provide a predetermined delay time equivalent to at least one pulse from said pulse width modulating means.

Claim 138

Dependent Claim 20 words

The laundering apparatus as set forth in claim 116 wherein said pulse width modulating means has a fixed pulse frequency.

Claim 139

Dependent Claim 199 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated, two-speed DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of winding stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause notation of said rotatable assembly means; means for sensing a back emf signal indicative of the back emf condition of at least one winding stage; means for integrating a portion of the back emf sig-nal and for producing a commutation signal indicative of a predetermined angular position of said rotatable assembly means; and control signal means responsive to the commutation signal for providing the set of control signals to said commu-tating means to commutate said winding stages when said rotat-able assembly means reaches the predetermined angular posi-tion; and means responsive to a speed control signal for pro-viding two different time constants for said integrating means corresponding to the two speeds of said DC motor.

Claim 140

Dependent Claim 199 words

A laundering apparatus comprising in combina-tion: a rotatable component; an electronically commutated, two-speed DC motor, said motor comprising rotatable assembly means for driving the rotatable component and a stationary assembly with a plurality of winding stages; a control system connected to said motor; and means for applying a DC voltage to said control sys-tem; said control system including means responsive to a set of control signals for commutating said winding stages by applying the DC voltage thereto in at least one preselected sequence to cause notation of said rotatable assembly means; means for sensing a back emf signal indicative of the back emf condition of at least one winding stage; means for integrating a portion of the back emf sig-nal and for producing a commutation signal indicative of a predetermined angular position of said rotatable assembly means; and control signal means responsive to the commutation signal for providing the set of control signals to said commu-tating means to commutate said winding stages when said rotat-able assembly means reaches the predetermined angular posi-tion; and means responsive to a speed control signal for pro-viding two different time constants for said integrating means corresponding to the two speeds of said DC motor.

Claim 141

Dependent Claim 48 words

The laundering apparatus system as set forth in claim 118 further comprising digital delay means for inhib-iting the operation of said integrating means for a predeter-mined interval of time after the occurrence of the commutation pulse whereby commutation currents are prevented from being integrated by said integrating means.

Claim 142

Dependent Claim 48 words

The laundering apparatus as set forth in claim 118 further comprising means for approximating a neutral con-ductor voltage for said DC motor and wherein said back emf sensing means includes means for comparing the approximated neutral conductor voltage with the back emf of one of said winding stages.

Claim 143

Independent Claim 120 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and. a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving an effective DC voltage for application to the motor; commutating the winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotatable assembly; approximating a neutral conductor voltage for the DC motor; and comparing the approximated neutral conductor voltage with the back emf of one of the winding stages, the result of the comparison representing the angular position of the rotat-able assembly; the commutation of the winding stages occurring when the rotatable assembly reaches a predetermined angular posi-tion.

Claim 144

Independent Claim 120 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and. a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving an effective DC voltage for application to the motor; commutating the winding stages by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotatable assembly; approximating a neutral conductor voltage for the DC motor; and comparing the approximated neutral conductor voltage with the back emf of one of the winding stages, the result of the comparison representing the angular position of the rotat-able assembly; the commutation of the winding stages occurring when the rotatable assembly reaches a predetermined angular posi-tion.

Claim 145

Dependent Claim 53 words

The method as set forth in claim 121 wherein the DC motor has three winding stages, the effective voltage being provided to only two of the stages at a time, the ap-proximating step including summing the terminal voltages of the two stages to which the effective voltage is being pro-vided at that time.

Claim 146

Independent Claim 153 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving an effective DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; approximating a neutral conductor voltage for the DC motor; comparing the approximated neutral conductor voltage with the back emf of one of the-winding stages to provide a signal representing the angular position of the rotatable as-sembly; integrating the angular position signal; generating a commutation signal when the integration result reaches a predetermined level; and providing the set of control signals in response to the commutation signal to commutate the winding stages when the rotatable assembly reaches a predetermined angular posi-tion.

Claim 147

Independent Claim 153 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving an effective DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; approximating a neutral conductor voltage for the DC motor; comparing the approximated neutral conductor voltage with the back emf of one of the-winding stages to provide a signal representing the angular position of the rotatable as-sembly; integrating the angular position signal; generating a commutation signal when the integration result reaches a predetermined level; and providing the set of control signals in response to the commutation signal to commutate the winding stages when the rotatable assembly reaches a predetermined angular posi-tion.

Claim 148

Dependent Claim 32 words

The method as set forth in claim 123 including the further step of pulse width modulating the set of control signals, whereby the resultant effective voltage is provided to the winding stages.

Claim 149

Dependent Claim 72 words

The method as set forth in claim 124 wherein the effective voltage is provided to less than all the winding stages at a time, the back emf signal for the comparison being obtained from a winding stage not having the effective voltage applied to it at that time, and the approximating step includ-ing summing the terminal voltages of the winding stages to which the effective voltage is being provided at that time.

Claim 150

Dependent Claim 68 words

The method as set forth in claim 125 wherein the DC motor has three winding stages, the effective voltages being provided to only two of the winding stages at a time, the third winding stage providing the back emf signal for the comparison, and the approximating step including summing the terminal voltages of the two winding stages to which the ef-fective voltage is being provided at that time.

Claim 151

Independent Claim 165 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; sensing a back emf signal indicative of the back emf condition of at least one winding stage; integrating a portion of the back emf signal to pro-duce an output indicative of the angular position of the ro-tatable assembly; generating a commutation signal when the integration output reaches a predetermined level; providing the set of control signals in response to receipt of a signal to commutate the winding stages; and providing a signal to initiate rotation of the ro-tatable assembly unless the commutation signal is generated before the expiration of a predetermined time interval

Claim 152

Independent Claim 165 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; sensing a back emf signal indicative of the back emf condition of at least one winding stage; integrating a portion of the back emf signal to pro-duce an output indicative of the angular position of the ro-tatable assembly; generating a commutation signal when the integration output reaches a predetermined level; providing the set of control signals in response to receipt of a signal to commutate the winding stages; and providing a signal to initiate rotation of the ro-tatable assembly unless the commutation signal is generated before the expiration of a predetermined time interval

Claim 153

Independent Claim 179 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving an effective DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; sensing a back emf signal indicative of the back emf condition of at least one winding stage; integrating a portion of the back emf signal and producing a commutation signal indicative of a predetermined angular position of the rotatable assembly; providing the set of control signals in response to the commutation pulse to commutate the winding stages when the rotatable assembly reaches the predetermined angular position; digitally restarting the integration each time the winding stages are commutated; and inhibiting the integration for a predetermined inte-rval of time after the occurrence of the commutation signal, whereby commutation currents are prevented from being inte-grated by the integrating means.

Claim 154

Independent Claim 179 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving an effective DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; sensing a back emf signal indicative of the back emf condition of at least one winding stage; integrating a portion of the back emf signal and producing a commutation signal indicative of a predetermined angular position of the rotatable assembly; providing the set of control signals in response to the commutation pulse to commutate the winding stages when the rotatable assembly reaches the predetermined angular position; digitally restarting the integration each time the winding stages are commutated; and inhibiting the integration for a predetermined inte-rval of time after the occurrence of the commutation signal, whereby commutation currents are prevented from being inte-grated by the integrating means.

Claim 155

Dependent Claim 26 words

The method as set forth in claim 128 wherein the predetermined interval of time corresponds to approximate-ly twenty electrical degrees of rotation of the rotatable as-sembly.

Claim 156

Dependent Claim 46 words

The method as set forth in claim 128 further including the step of approximating a neutral conductor volt-age for the DC motor and wherein the back emf sensing step in-cludes comparing the approximated neutral conductor voltage with the back emf of one of the winding stages.

Claim 157

Dependent Claim 28 words

The method as set forth in claim 130 wherein the approximating step includes summing the terminal voltages of less than all the winding stages at any particular time.

Claim 158

Dependent Claim 38 words

The method as set forth in claim 128 further including the step of digitally providing a starting pulse to initiate rotation of the rotatable assembly unless the commu-tation pulse occurs before the expiration of a predetermined time interval.

Claim 159

Dependent Claim 73 words

` 133. The method as set forth in claim 128 wherein the DC motor is a two-speed DC motor, and the integrating step including integrating at a first rate in response to one state of a speed control signal and integrating at a second rate in response to a second state of the speed control signal, the two states of the speed control signal corresponding to the two speeds of the DC motor.

Claim 160

Dependent Claim 54 words

The method as set forth in claim 128 further including the steps of pulse width modulating the set of con-trol signals, whereby the effective voltage is provided to the winding stages, and reducing the duty cycle of the pulses ap-plied to the winding stages in response to an applied voltage above a predetermined level.

Claim 161

Independent Claim 151 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; sensing a back emf signal indicative of the back emf condition of at least one winding stage; generating a commutation signal when the back emf signal indicates the rotatable assembly has reached a prede-termined angular position; providing the set of control signals in response to receipt of a signal to commutate the winding stages; and providing a signal to initiate rotation of the ro-tatable assembly unless the commutation signal is generated before the expiration of a predetermined time interval.

Claim 162

Independent Claim 151 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; sensing a back emf signal indicative of the back emf condition of at least one winding stage; generating a commutation signal when the back emf signal indicates the rotatable assembly has reached a prede-termined angular position; providing the set of control signals in response to receipt of a signal to commutate the winding stages; and providing a signal to initiate rotation of the ro-tatable assembly unless the commutation signal is generated before the expiration of a predetermined time interval.

Claim 163

Independent Claim 155 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving an effective DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; approximating a neutral conductor voltage for the DC motor; sensing a back emf signal indicative of the back emf condition of at least one winding stage to provide a commuta-tion pulse when the rotatable assembly reaches a predetermined angular position, the back emf sensing including comparing the approximated neutral conductor voltage with the back emf of one of the winding stages; and providing the set of control signals to commutate the winding stages when the rotatable assembly reaches the predetermined angular position.

Claim 164

Independent Claim 155 words

A method of operating an electronically commu-tated DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving an effective DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; approximating a neutral conductor voltage for the DC motor; sensing a back emf signal indicative of the back emf condition of at least one winding stage to provide a commuta-tion pulse when the rotatable assembly reaches a predetermined angular position, the back emf sensing including comparing the approximated neutral conductor voltage with the back emf of one of the winding stages; and providing the set of control signals to commutate the winding stages when the rotatable assembly reaches the predetermined angular position.

Claim 165

Dependent Claim 28 words

The method as set forth in claim 136 wherein the approximating step includes summing the terminal voltages of less than all the winding stages at any particular time.

Claim 166

Dependent Claim 38 words

The method as set forth in claim 136 further including the step of digitally providing a starting pulse to initiate rotation of the rotatable assembly unless the commu-tation pulse occurs before the expiration of a predetermined time interval.

Claim 167

Dependent Claim 54 words

The method as set forth in claim 136 further including the steps of pulse width modulating the set of con-trol signals, whereby the effective voltage is provided to the winding stages, and reducing the duty cycle of the pulses ap-plied to the winding stages in response to an applied voltage above a predetermined level.

Claim 168

Independent Claim 142 words

A method of operating an electronically commu-tated motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; sensing the angular position of the rotatable assem-bly and providing a commutation signal indicative of a prede-termined angular position of the rotatable assembly; providing the set of control signals to commutate the winding stages when the rotatable assembly reaches the predetermined angular position; and inhibiting the generation of the set of control sig-nals when the motor current exceeds a predetermined maximum value, the inhibition being maintained until it is manually overridden.

Claim 169

Independent Claim 142 words

A method of operating an electronically commu-tated motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rotat-able assembly; sensing the angular position of the rotatable assem-bly and providing a commutation signal indicative of a prede-termined angular position of the rotatable assembly; providing the set of control signals to commutate the winding stages when the rotatable assembly reaches the predetermined angular position; and inhibiting the generation of the set of control sig-nals when the motor current exceeds a predetermined maximum value, the inhibition being maintained until it is manually overridden.

Claim 170

Dependent Claim 43 words

The method as set forth in claim 140 wherein the inhibiting step includes temporarily inhibiting less than all the control signals when the motor current exceeds a sec-ond predetermined value, the second predetermined current val-ue being less than the predetermined maximum current value.

Claim 171

Dependent Claim 44 words

The method as set forth in claim 141 including sensing the voltage applied to the winding stages and tempo-rarily inhibiting all the control signals but one to reduce the effective voltage applied to the winding stages when the applied voltage exceeds a predetermined level.

Claim 172

Independent Claim 249 words

A method of operating an electronically commu-tated motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rota-table assembly, each winding stage having at least two termin-als, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is applied to pairs of other terminals of the winding stages in at least one preselected sequence; supplying the control signals in a sequence in which for each commutation one of the winding stages which was ener-gized before commutation remains energized after commutation and the other winding stage which was energized before commu-tation becomes deenergized after commutation, each winding stage remaining energized through two successive commutations unique to it and then becoming deenergized, the direction of current flow in the winding stage which remains energized af-ter commutation being the same as the direction of current flow in that winding stage before commutation; and pulse width modulating the control signal associated with the winding stage which remains on after commutation un-til a predetermined time after commutation and shifting at that time to pulse width modulate the control signal associat-ed with the winding stage which will remain on after the next commutation.

Claim 173

Independent Claim 249 words

A method of operating an electronically commu-tated motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rota-table assembly, each winding stage having at least two termin-als, one of which is commonly connected to one terminal of each of the other winding stages and the DC voltage is applied to pairs of other terminals of the winding stages in at least one preselected sequence; supplying the control signals in a sequence in which for each commutation one of the winding stages which was ener-gized before commutation remains energized after commutation and the other winding stage which was energized before commu-tation becomes deenergized after commutation, each winding stage remaining energized through two successive commutations unique to it and then becoming deenergized, the direction of current flow in the winding stage which remains energized af-ter commutation being the same as the direction of current flow in that winding stage before commutation; and pulse width modulating the control signal associated with the winding stage which remains on after commutation un-til a predetermined time after commutation and shifting at that time to pulse width modulate the control signal associat-ed with the winding stage which will remain on after the next commutation.

Claim 174

Dependent Claim 104 words

The method as set forth in claim 143 wherein the winding stages have associated therewith first drive means for selectively allowing the flow of current through at least one of the winding stages in a first direction in response to some of the control signals and second drive means for selec-tively allowing the flow of current through at least one of the winding stages in the opposite direction in response to others of the control signals, wherein the pulse width modu-lating step includes modulating the control signals for the first drive means and the control signals for the second drive means substantially equal amounts.

Claim 175

Dependent Claim 102 words

The method as set forth in claim 144 further including generating a drive selection signal every other com-mutation, and shifting in response to a first state of the drive selection signal from modulating the control signals for the first drive means to modulating the control signals for the second drive means upon the expiration of the predeter-mined time after commutation and shifting in response to a se-cond state of the drive selection signal from modulating the control signals for the second drive means to modulating the control signals for the first drive means upon the expiration of the predetermined time after commutation.

Claim 176

Dependent Claim 71 words

The method as set forth in claim 143 further including sensing a back emf signal indicative of the back emf condition of at least one winding, integrating a portion of the back emf signal to produce an output indicative of the angular position of the rotatable assembly, and generating a commutation signal when the integration output reaches a pre-determined level, the commutation signal representing the angular position of the rotatable assembly.

Claim 177

Dependent Claim 58 words

The method as set forth in claim 146 including inhibiting the integration for the predetermined time after commutation, whereby commutation currents are prevented from being integrated by the integrating means, and shifting after the predetermined time after commutation to pulse width modu-late the control signal associated with the winding stage which will remain on after the next commutation.

Claim 178

Independent Claim 199 words

A method of operating an electronically com-mutated motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rota-table assembly, the winding stages being connected together at one end whereby the DC voltage is applied to a pair of winding stages at a time; supplying the control signals in a sequence in which for each commutation one of the winding stages which was ener-gized before commutation remains energized after commutation and the other winding stage which was energized before commu-tation becomes deenergized after commutation, each winding stage remaining energized through two successive commutations unique to it and then becoming deenergized, the direction of current flow in the winding stage which remains energized after commutation being the same as the direction of current flow in that winding stage before commutation; and pulse width modulating upon commutation the control signal associated with the winding stage which was just com-mutated on.

Claim 179

Independent Claim 199 words

A method of operating an electronically com-mutated motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding stages, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rota-table assembly, the winding stages being connected together at one end whereby the DC voltage is applied to a pair of winding stages at a time; supplying the control signals in a sequence in which for each commutation one of the winding stages which was ener-gized before commutation remains energized after commutation and the other winding stage which was energized before commu-tation becomes deenergized after commutation, each winding stage remaining energized through two successive commutations unique to it and then becoming deenergized, the direction of current flow in the winding stage which remains energized after commutation being the same as the direction of current flow in that winding stage before commutation; and pulse width modulating upon commutation the control signal associated with the winding stage which was just com-mutated on.

Claim 180

Dependent Claim 72 words

The method as set forth in claim 148 wherein each winding stage has associated therewith first drive means for allowing the flow of current through its associated wind-ing stage in a first direction in response to a first one of the control signals and second drive means for allowing the flow of current through its associated winding stage in the opposite direction in response to a second one of the control signals.

Claim 181

Dependent Claim 59 words

The method as set forth in claim 149 further including sensing the motor current and inhibiting generation of the set of control signals when the motor current exceeds a predetermined maximum value, thereby turning off the first and second drive means for all the winding stages, said inhibiting preventing the generation of control signals until it is manu-ally overridden.

Claim 182

Dependent Claim 56 words

The method as set forth in claim 150 including temporarily inhibiting all but one of the control signals when the motor current exceeds a second predetermined value, the second predetermined current value being less than the prede-termined maximum current value, whereby one of the drive means is left on to allow circulation of the winding currents.

Claim 183

Dependent Claim 46 words

The method as set forth in claim 151 including sensing the voltage applied to the winding stages and, in re-sponse to an applied voltage exceeding a predetermined level, temporarily inhibiting all the control signals but one to re-duce the effective voltage applied to the winding stages.

Claim 184

Dependent Claim 90 words

The method as set forth in claim 149 further including generating a drive selection signal every other com-mutation and in response to a first state of the drive selec-tion signal to shift from modulating the control signals for the first drive means to modulating the control signals for the second drive means upon commutation and in response to a second state of the drive selection signal to shift from modu-lating the control signals for the second drive means to modu-lating the control signals for the first drive means upon com-mutation.

Claim 185

Independent Claim 178 words

A method of operating a reversible, electron-ically commutated motor with the motor having a rotatable as-sembly and a stationary assembly with a plurality of winding stages, said method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages by applying the DC voltage thereto in a first sequence to cause rotation of the rotatable assembly in a first direction and commutating the winding stages by applying the DC voltage thereto in a second sequence to cause rotation of the rotatable assembly in a sec-ond direction, the particular sequence being determined by a direction signal; the commutation occurring in the first sequence when the state of the direction signal represents desired rotation in the first direction and the commutation occurring in the second sequence when the state of the direction signal repre-sents desired rotation in the second direction; and delaying the switching from one sequence to the other as required by a change in state of the direction signal until the expiration of a predetermined delay time after said change in state.

Claim 186

Independent Claim 178 words

A method of operating a reversible, electron-ically commutated motor with the motor having a rotatable as-sembly and a stationary assembly with a plurality of winding stages, said method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages by applying the DC voltage thereto in a first sequence to cause rotation of the rotatable assembly in a first direction and commutating the winding stages by applying the DC voltage thereto in a second sequence to cause rotation of the rotatable assembly in a sec-ond direction, the particular sequence being determined by a direction signal; the commutation occurring in the first sequence when the state of the direction signal represents desired rotation in the first direction and the commutation occurring in the second sequence when the state of the direction signal repre-sents desired rotation in the second direction; and delaying the switching from one sequence to the other as required by a change in state of the direction signal until the expiration of a predetermined delay time after said change in state.

Claim 187

Dependent Claim 37 words

The method as set forth in claim 154 further including pulse width modulating the application of the DC voltage to the winding stages, the predetermined delay time being equivalent to at least one pulse width modulation pulse.

Claim 188

Dependent Claim 19 words

The method as set forth in claim 155 wherein the pulse width modulation pulses occur at a fixed frequency.

Claim 189

Independent Claim 182 words

A method of operating an electronically com-mutated, two-speed DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding steps, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rota-table assembly; sensing a back emf signal indicative of the back emf condition of at least one winding; integrating a portion of the back emf signal and producing 2 commutation signal indicative of a predetermined angular position of the rotatable assembly, the integration occurring at a first rate when the motor is being operated at one speed and occurring at a second rate when the motor is being operated at the second speed, the rate of integration being determined by a speed control signal; and providing the set of control signals in response to the commutation signal to commutate the winding stages when the rotatable assembly reaches the predetermined angular position.

Claim 190

Independent Claim 182 words

A method of operating an electronically com-mutated, two-speed DC motor with the motor having a rotatable assembly and a stationary assembly with a plurality of winding steps, the method comprising the steps of: receiving a DC voltage for application to the motor; commutating the winding stages in response to a set of control signals by applying the DC voltage thereto in at least one preselected sequence to cause rotation of the rota-table assembly; sensing a back emf signal indicative of the back emf condition of at least one winding; integrating a portion of the back emf signal and producing 2 commutation signal indicative of a predetermined angular position of the rotatable assembly, the integration occurring at a first rate when the motor is being operated at one speed and occurring at a second rate when the motor is being operated at the second speed, the rate of integration being determined by a speed control signal; and providing the set of control signals in response to the commutation signal to commutate the winding stages when the rotatable assembly reaches the predetermined angular position.

Claim 191

Dependent Claim 39 words

The method as set forth in claim 157 further including digitally inhibiting the integration for a predetermined interval of time after the occurrence of the commutation signal, whereby commutation currents are prevented from being integrated by the integrated means.

Claim 192

Dependent Claim 43 words

The method as set forth in claim 157 further including approximating a neutral conductor voltage for the DC motor and wherein the back emf sensing step includes comparing the approximated neutral conductor voltage with the back emf of one of the winding stages.

Control system, method of operating an electronically commutated motor, and laundering apparatus

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag