Physical condition responsive transducer system, particularly magnetic field transducer system especially for use in or combination with brushless D-C motors

Claim 2

Magnetic field dependent transducer system for connection to supply terminals 15, 17 adapted to have a voltage appear thereacross, comprising two serially connected transducer elements 12, 13 responsive to a magnetic field and changing their respective electrical impedances in opposite directions in response to a unidirectional change in the magnetic field incident thereon, connected to said supply terminals, the voltage appearing at the common junction 14 of said serially connected elements being a function of the direction of the magnetic field acting on said elements; and a logic circuit 22 having two relatively opposite, complementary, essentially symmetrical outputs 23, 24 and having a supply terminal 29 connecting signals applied to said supply terminal, selectively, with one or the other of said outputs; the voltage of said junction 14 of the serially connected transducer elements being connected to the logic circuit 22 to control which one of said outputs 23 or 24 will be connected to said supply terminal 29.

Claim 3

System according to claim 1, wherein the logic circuit 22 is a non-symmetrical circuit and comprises a first semiconductor element 36 connected between the supply terminal 29 and one output 23; a second semiconductor element 37 connected between the supply terminal 29 and the other output 24; conduction of one of said semiconductor elements 36 being controllable, said one semiconductor element having, when in conductive condition, a lower forward voltage drop than the other, the voltage of said common junction 14 being connected to the controllable semiconductor elements to render said one semiconductor element either conductive, or non-conductive; and circuit means 32, 34; 33, 30 connected to the output terminals 23, 24 selectively inhibiting current flow to that selected output terminal which has the semiconductor element connected thereto having a higher forward voltage drop.

Claim 4

System according to claim 1, wherein the logic circuit 22 comprises a voltage controlled semiconductor element 36 connected to and controlled by the voltage appearing at said junction 14, said semiconductor element being connected in the circuit with said supply terminal 29 and controlling one of said outputs 23.

Claim 5

System according to claim 3, wherein the other output 24 of said logic circuit 22 is connected to said supply terminal 29 without interposition of a voltage controllable semiconductor element.

Claim 6

System according to claim 3, wherein a diode 37 is connected between the other output 24 of said logic circuit 22 and the supply terminal 29, the voltage controlled semiconductor element is a transistor, and the forward voltage drop of the diode is greater than the emitter-collector drop of the transistor when in conductive condition.

Claim 7

System according to claim 3, further comprising two controlled semiconductor elements 32, 33, one each being connected to an output terminal 23, 24 of the logic circuit 22; wherein said logic circuit is a non-symmetrical circuit and comprises a semiconductor element 37 having a fixed forward voltage drop connected between the supply terminal 29 and the other output 24, the total forward voltage drop of said semiconductor element 37 and the voltage drop of the control path of the controlled semiconductor element 33 connected to the other output being greater than the total forward voltage drop of said voltage controlled semiconductor element 36, when in conductive condition, and the voltage drop of the control path of the controlled semiconductor element 32 connected to said one output 23.

Claim 8

System according to claim 6, wherein the semiconductor element 37, the controlled semiconductor elements 32, 33, and the voltage controlled semiconductor element 36 comprise an integrated circuit.

Claim 9

System according to claim 3, comprising a voltage breakdown element 35 having Zener diode characteristics, connected in series with the junction 14 of the transducer elements 12, 13 and the voltage controlled semiconductor element 36.

Claim 10

System according to claim 1, wherein the transducer elements comprise magnetic field sensitive diodes 12, 13.

Claim 11

System according to claim 1, in combination with a brushless d-c motor 140 having armature windings 142, 143, an output transistor 32, 33, each, in series with a winding, and controlling current flow therethrough; the transistors being connected to respective outputs of the logic circuit, so that conduction of one or the other transistor 32, 33 will be controlled from the logic circuit, the extent of conduction being determined by the output signal from said logic circuit, as determined by the signal applied to said supply terminal 29 of the logic circuit 22.

Claim 12

System according to claim 10, further comprising means connecting a signal representative of commanded motor operating characteristics to said supply terminal 29.

Claim 13

System according to claim 10, further comprising means 151, 152; 156, 163 sensing the instant of commutation of conduction from one transistor to the other, said means being connected to and controlling the voltage applied to said supply terminal 29 to control the conduction of one or the other of the transistors to decrease current flow therethrough immediately prior to, or during commutation.

Claim 14

System according to claim 12, wherein said sensing means comprises means 151, 152 sensing induced voltage in the armature coils of the motor; phase shift means 154-160 phase-shifting said sensed voltage by about 180*, and means 163 controlling the voltage applied to said supply terminal 29 under command of said phase-shifted, sensed voltage.

Claim 15

System according to claim 10, wherein the motor has a permanent magnet rotor and wherein said serially connected transducer elements comprise magnetic diodes 12, 13 which are magnetically, relatively oppositely located and arranged on the stator of the motor to be subjected to the field of the rotor of the motor.

Claim 16

System according to claim 14, wherein the logic circuit 22 comprises a voltage controlled semiconductor element 36 connected to and controlled by the voltage appearing at said junction 14, said semiconductor element being connected in the circuit with said supply terminal 29 and controlling one of said outputs 23.

Claim 17

System according to claim 15, wherein the other output 24 of said logic circuit 22 is connected to said supply terminal 29 without interposition of a voltage controllable semiconductor element.

Claim 18

System according to claim 16, wherein said logic circuit is a non-symmetrical circuit and comprises a semiconductor element 37 having a fixed forward voltage drop connected between the supply terminal 29 and the other output 24 of the logic circuit, the total forward voltage drop of said semiconductor element 37 and the voltage drop of the control path of the transistor 33 connected to the other output 24 being greater than the total forward voltage drop of said voltage controlled semiconductor element 36, when in conductive condition, and the voltage drop of the control path of the transistor 32 which is connected to said one output 23 of the logic circuit.

Claim 19

System according to claim 15, comprising a voltage breakdown element 35 having Zener diode characteristics, connected in series with the junction 14 of the transducer elements 12, 13 and the voltage controlled semiconductor element 36.

Claim 20

System according to claim 14, including means 154, 155, 156 coupled 151, 152 to at least one of the armature windings 142, 143 of the motor, and deriving an undulating d-c voltage from said windings, the frequency of undulation 93 being representative of motor speed; means deriving an undulating a-c component of said d-c voltage and means connected to and controlling the voltage applied to the supply terminals 29 of the logic circuit controlled by said undulating a-C component 94.

Claim 21

System according to claim 19, wherein said undulating a-c component deriving means senses the minimum point at the undulating voltage, and includes phase-shift means 153- 155, 157'', 160 to place the occurrence of said minimum approximately symmetrically between the commutating instants (FIG. 4, t2, t5).

Claim 22

Condition responsive transducer system for connection to voltage supply terminals adapted to have a voltage appear thereacross 15, 17 providing a controlled output depending on a control signal, at a selected output terminal 23, 24 as a function of a predetermined external condition to which said system is responsive, comprising two serially connected transducer elements 12, 13 responsive to a physical condition, or parameter, and each changing its electrical impedance in a first direction in response to a change in the condition, in a predetermined direction, to which the element is responsive, said serially connected elements being connected to the supply terminals; means 14 deriving a voltage appearing at the common junction connection of said serially connected elements, said voltage being a function of response of at least one, or the other of said elements to occurrence of said condition; and a logic circuit 22 having two relatively opposite, complementary, essentially symmetrical outputs 23, 24, said logic circuit having a supply terminal 29 connecting said control signal applied to said supply terminal, selectively, with one or the other of said outputs 23, 24; the voltage derived by said voltage deriving means at said junction being connected to the logic circuit 22 to control which one of said outputs 23 or 24 will be connected to said supply terminal 29.

Claim 23

Condition responsive transducer system for connection to voltage supply terminals adapted to have a voltage appear thereacross 15, 17 providing a controlled output depending on a control signal, at a selected output terminal 23, 24 as a function of a predetermined external condition to which said system is responsive, comprising two serially connected transducer elements 12, 13 responsive to a physical condition, or parameter, and each changing its electrical impedance in a first direction in response to a change in the condition, in a predetermined direction, to which the element is responsive, said serially connected elements being connected to the supply terminals; means 14 deriving a voltage appearing at the common junction connection of said serially connected elements, said voltage being a function of response of at least one, or the other of said elements to occurrence of said condition; and a logic circuit 22 having two relatively opposite, complementary, essentially symmetrical outputs 23, 24, said logic circuit having a supply terminal 29 connecting said control signal applied to said supply terminal, selectively, with one or the other of said outputs 23, 24; the voltage derived by said voltage deriving means at said junction being connected to the logic circuit 22 to control which one of said outputs 23 or 24 will be connected to said supply terminal 29.

Claim 24

System according to claim 21, wherein the logic circuit 22 is a non-symmetrical circuit and comprises a first semiconductor element 36 connected between the supply terminal 29 and one output 23; a second semiconductor element 37 connected between the supply terminal 29 and the other output 24; conduction of one of said semiconductor elements 36 being controllable, said one semiconductor element having, when in conductive condition, a lower forward voltage drop than the other, the voltage of said common junction 14 being connected to the controllable semiconductor elements to render said one semiconductor element either conductive, or non-conductive; and circuit means 32, 34; 33, 30 connected to the output terminals 23, 24 selectively inhibiting current flow to that selected output terminal which has the semiconductor element connected thereto having a highere forward voltage drop.

Claim 25

System according to claim 21, wherein the logic circuit 22 comprises a voltage controlled semiconductor element 36 connected to and controlled by the voltage appearing at said junction 14, said semiconductor element being connected in the circuit with said supply terminal 29 and controlling one of said outputs 23; two controlled semiconductor elements 32, 33, one each being connected to an output terminal 23, 24 of the logic circuit 22; wherein said logic circuit is a non-symmetrical circuit and comprises a semiconductor element 37 having a fixed forward voltage drop connected between the supply terminal 29 and the other output 24, the total forward voltage drop of said semiconductor element 37 and the voltage drop of the control path of the controlled semiconductor element 33 connected to the other output being greater than the total forward voltage drop of said voltage controlled semiconductor element 36, when in conductive condition, and the voltage drop of the control path of the controlled semiconductor element 32 connected to said one output 23.

Claim 26

System according to claim 21, in combination with a brushless d-c motor 140 having armature windings 142, 143, an output transistor 32, 33, each, in series with a winding, and controlling current flow therethrough; the transistors being connected to respective ouTputs of the logic circuit, so that conduction of one or the other transistor 32, 33 will be controlled from the logic circuit, the extent of conduction being determined by the output signal from said logic circuit, as determined by the signal applied to said supply terminal 29 of the logic circuit 22, said control signal being representative of a commanded motor operating condition.