Electronically commutated motor and method to drive the same

摘要

The motor has a rotor and a stator, a stator winding arrangement supplied with current from a D.C. source via a full bridge with an upper MOSFET connected to the positive supply line and a lower transistor connected to the negative line in each arm, and a commutating arrangement for the transistors. An arrangement alters the duty ratio of a PWM signal controlling the bridge depending on at least one motor parameter to reduce the current generated by the motor if the braking current exceeds a defined value.