CONTROL CIRCUIT FOR PRE-HEATER OF VEHICLE

摘要

PURPOSE: A control circuit for a vehicle pre-heater is provided to supply sufficient gate-driving voltages by applying the gate-side drive signals of a switching device as PWM(Pulse Width Modulation) signals using a transformer. CONSTITUTION: A control circuit for a vehicle pre-heater consists of a microprocessor(1), a PWM drive(100), a switching device(3), a fault detector(5), and a signal-transfer photo-coupler(200). The PWM drive is composed of a pulse generator(110), a transformer(120), and a PWM-transfer photo-coupler(130). The PWN-transfer photo-coupler consists of a light emitting device(131) driven by the PWM signals of the microprocessor and a light receiving device(132) receiving the secondary output of the transformer and outputs the gate-driving signals of the switching device. The signal-transfer photo-coupler consists of a light emitting device(201) driven by the fault detecting signals of the fault detector and a light receiving device(202) transferring the fault detecting signals to the microprocessor.