SPEED CONTROLLER FOR WIPER MOTOR FOR MOTOR CAR

摘要

PURPOSE:To steplessly regulate the speed of a wiper motor by controlling the duty of a control signal by a deviation between a rotating speed and a set rotating speed. CONSTITUTION:When a semiconductor switching element 2 repeats ON and OFF, a voltage smoothed by a smoothing circuit 3 is applied to a wiper motor 1. A rotating speed detector 5 calculates the voltage and current applied to the motor 1 to obtain a rotating speed. A comparator 7 compares a rotating speed with a set rotating speed value, and outputs a deviation signal. A duty controller 8 applies a pulse signal controlled in the duty in response to the deviation signal through a drive circuit 4 to the element 2. High frequency noise generated by the ON and OFF of the element 2 is removed by a high frequency removing filter 9.