BATTERY FED D.C. MOTOR CONTROL SYSTEM

摘要

Electric power control system useful for controlling the torque of a direct current electric motor which forms a portion of an electrical power circuit. Power for the circuit is derived from a bank of batteries. The control system comprises a current sensing device in the power circuit having an output that constitutes a correction voltage proportional to current flow. A variable reference voltage control device varies the reference voltage. There is a series pass transistor in the electrical power circuit. A linear operational amplifier in the emitter circuit of the series pass transistor is coupled as a comparator to both the correction voltage and reference voltage. The amplifier has an output voltage that varies in response to differences between the correction and reference voltages. The output of the amplifier is connected to the base of the transistor so that the output voltage controls the equivalent resistance of the transistor. The circuit is arranged so that for any one reference voltage the current flow through the electrical power circuit is approximately constant.