Patent ID: 6917172

Claim:
A motor controller for an electric motor having plurality of motor terminals, the motor controller being connected to a power supply and comprising: a commutation control connected to the motor terminals for causing current pulses to flow through selected terminals during each commutation state; a current senor for providing a sense signal representative of the current pulses; a peak current target circuit for providing a target signal; a pulse width control for controlling pulse width of the current pulses as a function of the sense signal and the target signal wherein the pulse width control includes a comparator which compares the sense signal and the target signal and a pulse generator which supplies a control pulse to the commutation control when the comparator provides an output indicating that the sense signal has reached the target signal; and a reverse current control for preventing reverse current from flowing into the power supply during change of commutation state, wherein the reverse current control resets the pulse generator at the start of each change of commutation state in which a new motor terminal is connected to a high power supply voltage.