CONTROLLER OF NUMBER OF REVOLUTIONS OF AIR CONDITIONING FAN MOTOR

摘要

PROBLEM TO BE SOLVED: To reduce electromagnetic noise generated from a motor when a fan of an air conditioner is rotated. SOLUTION: In a controlling device of the number of revolutions of a fan motor for air conditioning which is driven with the number of revolutions made variable, a switching element driving circuit 4 having two switching elements 2 which are IGBTs or power MOSFETs and a bridge circuit 3 for making a current flow in a prescribed direction for the two switching elements 2 are provided, and a PWM signal for driving the fan motor 1 for air conditioning is set at the duty of the number of revolutions being a target.