Abstract: A regenerative braking control apparatus for use with a motor driven by a D.C. power source. In response to a series of operating parameters, the control apparatus causes the motor to transition between a drive mode, a transient mode, a regulated current regenerative braking mode, and a constant PWM regenerative braking mode. In particular, the motor enters the drive mode in response to a request for an increase in speed, the motor enters the transient mode in response to a request for a decrease in speed, the motor enters the regulated current regenerative braking mode in response to a lapse of a predetermined time delay or in response to a request for a reduction in the magnitude of the previously requested decrease in speed, and the motor enters the PWM regenerative braking mode in response to a request to continue braking when the requested braking torque cannot be maintained.

Abstract: A motor controller comprises a plug detect circuit which detects "continuous" plug diode conduction during plug braking. The plug detect circuit detects "continuous" plug braking by detecting when a plug diode is or is not conducting current throughout substantially the entire time that a power MOSFET controlling the plug braking is conductive in one pulse width modulated MOSFET switching cycle. Continuous plug detection facilitates the motor controller's controlling a vehicle so that the vehicle has a more constant and smooth plug braking deceleration and subsequent powered acceleration in the opposite direction. According to another aspect of the invention, a motor controller comprises a POT HI and a POT LO driver circuit. The POT HI and POT LO driver circuits allow the detection of faults in throttle devices and the connections of the throttle devices to the POT HI and POT LO driver circuits.