CURRENT LIMIT CONTROL CIRCUIT

摘要

Apparatus (10) is provided for controlling current through a motor (12), including a circuit (14) for generating motor speed command data, a circuit (26) for generating a control signal in response to a maximum value of current through the motor (12), a programmable data processor (72) for generating pulse trains in response to the command data, and a controllable supplying circuit (18) for coupling and decoupling power to the motor (12) in response to the pulse trains and for decoupling power to the motor (12) in response to the control signal independent of the pulse trains. By decoupling power from the motor (12) independent of the control produced by the data processor (72), the current limit is achieved even if the data processor (72) malfunctions, contrary to prior apparatus.