Motor speed control

Claim 2

A motor speed control device comprising a source of DC power, an electric motor, transistor means having the emitter and collector thereof connected in series with said motor across said source for controlling current flow to the motor with said emitter connected to one side of said source and with said motor connected between said collector and the other side of said source, and resistance connecting the base of said transistor means to the collector thereof for controlling the speed of the motor.

Claim 3

The invention as defined in claim 1 wherein said resistance is a manually adjustable variable resistance for varying the speed of said motor.

Claim 4

A motor speed control and speed regulating system comprising a DC motor, a source of power, transistor means including base, collector, and emitter electrodes, circuit means connecting said DC motor and the emitter and collector electrodes of said transistor means in series across said source of power, a variable resistance, and control means including said variable resistance to apply a signal to the base of said transistor means varying in accordance with the setting of said variable resistance to control the speed of said motor, said control means including feedback means responsive to the condition of said motor to feedback a signal to the base of said transistor means to regulate the speed of said motor to reduce changes in speed under varying load conditions.

Claim 5

A motor speed control and speed regulating system comprising a DC motor, a source of power, transistor means including base, collector, and emitter electrodes, circuit means connecting said DC motor and the emitter and collector electrodes of said transistor means in series across said source of power, a variable resistance, and control means including said variable resistance to apply a signal to the base of said transistor means varying in accordance with the setting of said variable resistance to control the speed of said motor, said control means including feedback means responsive to the condition of said motor to feedback a signal to the base of said transistor means to regulate the speed of said motor to reduce changes in speed under varying load conditions.

Claim 6

A motor speed control and regulating system as recited in claim 3 wherein said transistor means includes a plurality of transistors connected in a plurality of amplification stages including at least an input transistor connected as a first amplification stage and an output transistor connected as the last amplification stage of the transistor means, the base of said input transistor being the base of said transistors means and the emitter and collector of said output transistor being the emitter and collector of said transistor means, the emitter of the transistor of each amplification stage of said transistor means except the last amplification stage being connected to the base of the transistor of the next succeeding amplification stage of said transistor means.

Claim 7

A motor speed control system comprising a DC motor, a source of power, a current amplifier connected in series with said motor across said source of DC power, feedback means to apply current to the input of said amplifier and responsive to changes in the condition of said motor to change the current applied to the input of said amplifier in the direction to counteract such change in condition of said motor, said current applied to the input of said amplifier by said feedback means flowing between said input of said amplifier and the junction between said amplifier and said motor in a current path defined by said feedback means.

Claim 8

A motor speed control system comprising a DC motor, a source of power, a current amplifier connected in series with said motor across said source of DC power, feedback means to apply current to the input of said amplifier and responsive to changes in the condition of said motor to change the current applied to the input of said amplifier in the direction to counteract such change in condition of said motor, said current applied to the input of said amplifier by said feedback means flowing between said input of said amplifier and the junction between said amplifier and said motor in a current path defined by said feedback means.

Claim 9

A system as recited in claim 5 wherein said feedback means comprises a resistance connected between said input of said amplifier and said junction.

Claim 10

A system as recited in claim 6 wherein said resistance is a variable resistor.

Claim 11

A system as recited in claim 5 wherein said feedback means includes means to vary the current applied to the input of said amplifier independently of said condition of said motor.

Claim 12

A system as recited in claim 5 wherein said condition is motor speed whereby said feedback means changes the current applied to the input of said amplifier upon changes of motor speed in a direction to counteract such changes in motor speed.