Heater controlling apparatus for car window.

摘要

In a window heater controlling apparatus used in an automobile, a heater control unit including a microcomputer is employed to detect a heater-ON condition and thereafter to control the heating voltage of the alternator in such a manner that the heating voltage is gradually increased up to the rated heating voltage at the beginning of the heater control operation. This heater control operation is performed by the duty ratio control of the switching transistor.