Motor control circuit has switch with control input coupled to PWM circuit, first connection to coil in motor circuit, second connection connected to first partly based on PWM signal

摘要

The motor control circuit (12) has a variable working cycle pulse width modulation circuit (24) for generating a variable working cycle PWM signal. The mean of the variable working cycle corresponds approximately to a desired motor revolution rate. A switch (26) has a control input from the PWM circuit, a first connection to a coil (18) in a motor circuit (10) and a second connection connected to the first partly based on the PWM signal. Independent claims are also included for the following: a method of controling a motor circuit.