MOTOR CONTROLLER AND ELECTRIC POWER TOOL HAVING THE SAME

摘要

A motor controller is provided with a first PWM circuit that repeatedly outputs an on-signal at a first carrier frequency, a second PWM circuit that repeatedly outputs an on-signal at a second carrier frequency that is lower than the first carrier frequency, an AND circuit that receives both the on-signal outputted from the first PWM circuit and the on-signal outputted from the second PWM circuit and outputs a third on-signal which is a logical product of the received on-signals, and a voltage apply circuit that applies a voltage to the motor intermittently in synchronization with the third on-signal outputted from the AND circuit. At least one of the first carrier frequency and the second carrier frequency is equal to or lower than 1 kHz or equal to or higher than 3 kHz. As a result, generation of an unpleasant noise by a motor controller using two PWM circuits may be suppressed.