POWER SOURCE SWITCHING DEVICE FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To provide a power source switching device for a vehicle simple in constitution capable of driving a switch means for switching power supply to an electric component required for maintaining the traveling of a vehicle by a double system during traveling. SOLUTION: This power source switching device 10 for a vehicle comprises a microcomputer 12, a relay driving circuit 13, a relay driving circuit 14, and a F-V conversion circuit 15. Vehicle speed pulses 17 outputted from a vehicle speed sensor 16 are inputted to the F-V conversion circuit 15 via a signal input terminal 24. The F-V conversion circuit 15 outputs driving signals to the relay driving circuit 14 while the vehicle speed pulses 17 are inputted so as to actuate an IG relay 11 and maintain it in an actuated state. COPYRIGHT: (C)2008,JPO&INPIT