Patent ID: 6747422
Filing Date: 2004-06-08
Classification: H02H,H05B,Y02B

Abstract:
An apparatus for protecting an electric device for a vehicle in which an electric device for a vehicle is operated by a power from a direct current power source mounted on the vehicle, the apparatus comprising:a MOB transistor a gate of which is connected to a side of an anode of the direct current power source and a source and a drain of which is connected to a ground side of the direct current power source, application of a reverse voltage to the electric device for the vehicle being interrupted by a withstand voltage between the drain and the source of the MOB transistor when the direct current power source is mounted to the vehicle with a polarity thereof inverted; and conducting means for bringing the MOB transistor into a conductive state even when the reverse voltage of negative polarity is caused on the anode side of the direct current power source by turning off an ignition switch of the vehicle.