Control for series shunt motor

Claim 2

A control circuit for interconnecting a source of electrical power with a direct current motor comprising: a. first switching means selectively operable for determining the direction of current through a field winding of the motor with respect to the direction of current through an armature of the motor; b. second switching means operable to select between a series connection mode and a shunt connection mode for the motor; c. control means to selectively adjust the average power supplied to said to the motor from the source in both said series mode and said shunt mode comprising means for the varying the ratio of on time to off time so that the motor and the source are connected; and d. means for coupling said second switching means to said control means for causing said second switching means to be operated as a function of the status of said control means.

Claim 3

The invention in accordance with claim 1 wherein said control means acts substantially at the time of transition between a series and a shunt mode of motor connection to change said ratio of on time to off time.

Claim 4

The invention in accordance with claim 2 wherein the change in said ratio is an inversion between a relatively high value and a relatively low value.

Claim 5

The invention in accordance with claim 1 further including means operable when said motor is in said shunt mode to limit the amount of armature current of said motor.

Claim 6

The invention in accordance with claim 4 wherein said last recited means limits said current by placing the motor in the series mode.

Claim 7

The invention in accordance with claim 1 wherein said control means includes manually adjustable means to vary said ratio of on time to off time.

Claim 8

The invention in accordance with claim 6 wherein said manually adjustable means is a potentiometer.

Claim 9

The invention in accordance with claim 7 wherein the effective value of the potentiometer varies, at the time of transition between a series mode and a shunt mode of motor connection, between a relatively high value and a relatively low value.

Claim 10

The invention in accordance with claim 1 wherein said control means serves to adjust the armature current and the field current in the series mode and only the field current in the shunt mode.

Claim 11

In combination with a source of electrical power and a direct current motor having an armature and a field, the motor being selectively operable in either a series mode or a shunt mode, means for governing the operation of said motor, comprising: a. first switching means for selecting the relative direction of current through said armature and said field for determining the direction of torque supplied by the motors; b. control means operable to vary the average power supplied from the source to the motor in each of said modes including means for varying the percentage of total time the source is connected to at least the field; and c. second switching means responsive to predetermined conditions within said control means for automatically selecting between said series mode and said shunt mode of motor operation.

Claim 12

In combination with a source of electrical power and a direct current motor having an armature and a field, the motor being selectively operable in either a series mode or a shunt mode, means for governing the operation of said motor, comprising: a. first switching means for selecting the relative direction of current through said armature and said field for determining the direction of torque supplied by the motors; b. control means operable to vary the average power supplied from the source to the motor in each of said modes including means for varying the percentage of total time the source is connected to at least the field; and c. second switching means responsive to predetermined conditions within said control means for automatically selecting between said series mode and said shunt mode of motor operation.

Claim 13

The invention in accordance with claim 10 wherein said percentage is varied by changing the ratio of on time to off time that the source and the field are connected.

Claim 14

The invention in accordance with claim 10 wherein said second switching means is responsive to predetermined values of current through said armature.

Claim 15

The invention in accordance with claim 10 wherein said control means acts at substantially the time of transition between a series mode and a shunt mode of motor connection to automatically change said percentage of time.

Claim 16

The invention in accordance with claim 10 wherein said source of electrical power is a battery.

Claim 17

A control circuit for interconnecting a source of electrical power with a direct current motor selectively operable in a series mode and a shunt mode of operation comprising: a. a master switch selectively operative to connect and disconnect said source to said motor, said master switch also providing means to select the direction of current through a field winding in said motor; b. a plurality of contacts to provide selection between a series connection mode and a shunt connection mode of said field winding of said motor; c. a potentiometer to adjust the speed of the motor by controlling the ratio of on time to off time of power through said motor. d. a contact arrangement to selectively invert said ratio of on time to off time upon transition between said connection modes; and, e. a current sensing circuit responsive to current through the armature of said motor to alter the average power provided by said control means.

Claim 18

A control circuit for interconnecting a source of electrical power with a direct current motor selectively operable in a series mode and a shunt mode of operation comprising: a. a master switch selectively operative to connect and disconnect said source to said motor, said master switch also providing means to select the direction of current through a field winding in said motor; b. a plurality of contacts to provide selection between a series connection mode and a shunt connection mode of said field winding of said motor; c. a potentiometer to adjust the speed of the motor by controlling the ratio of on time to off time of power through said motor. d. a contact arrangement to selectively invert said ratio of on time to off time upon transition between said connection modes; and, e. a current sensing circuit responsive to current through the armature of said motor to alter the average power provided by said control means.

Claim 19

The invention according to claim 15 wherein the current sensing circuit increases the field current as a direct function of the increase in armature current.

Claim 20

A control for an electric motor powered vehicle in which said motor derives power from a direct current source comprising: a. a first switching means selectively operable for determining the direction of current through a field winding of said motor with respect to the direction of current through an armature of said motor whereby the direction of torque supplied by said motor may be changed; b. a second switching means operable to select between a series connection mode and a shunt connection mode of said motor; c. a control means to selectively adjust the average power supplied to said motor from said source in both said series mode and in said shunt mode comprising means for varying the percentage of time that said source and said motor are connected; and d. means for coupling said second switching means to said control means for causing said second switching means to operate in response to the occurrence of predetermined conditions within said control means.

Claim 21

A control for an electric motor powered vehicle in which said motor derives power from a direct current source comprising: a. a first switching means selectively operable for determining the direction of current through a field winding of said motor with respect to the direction of current through an armature of said motor whereby the direction of torque supplied by said motor may be changed; b. a second switching means operable to select between a series connection mode and a shunt connection mode of said motor; c. a control means to selectively adjust the average power supplied to said motor from said source in both said series mode and in said shunt mode comprising means for varying the percentage of time that said source and said motor are connected; and d. means for coupling said second switching means to said control means for causing said second switching means to operate in response to the occurrence of predetermined conditions within said control means.

Claim 22

The invention in accordance with claim 17 wherein said control means is adjusted by means of an accelerator associated with said vehicle.

Claim 23

The invention in accordance with claim 18 wherein said accelerator serves to control a potentiometer which serves to adjust said average power.

Claim 24

The invention in accordance with claim 19 wherein said control means acts at the time of transition between a series mode and a shunt mode of motor connection to change the then effective value of said potentiometer.

Claim 25

The invention in accordance with claim 20 wherein the change in the effective value of the potentiometer is between a relatively high and a relatively low value.

Claim 26

The invention in accordance with claim 17 wherein said direct current source is a battery.