Alexander Charles Lawhon

US Patent:

20020109952, Aug 15, 2002

Filed:

Feb 12, 2001

Appl. No.:

09/780711

Inventors:

Robert Rapsinski - Kokomo IN, US
Alexander Lawhon - Kokomo IN, US
Desmond Ang - Kokomo IN, US

International Classification:

H02H003/18

US Classification:

361/086000, 361/091100

Abstract:

An improved over-voltage protection circuit for a motor vehicle electrical system includes an over-voltage responsive circuit for momentarily disconnecting the vehicle storage battery and alternator from vehicle electrical loads, and an auxiliary storage battery for supplying a safe operating voltage to the electrical loads during the momentary disconnection. The over-voltage responsive circuit includes a MOSFET device that couples the vehicle storage battery and alternator to the electrical loads and auxiliary storage battery, and a voltage responsive circuit that turns the MOSFET device off to decouple the electrical loads and auxiliary storage battery from the vehicle storage battery and alternator so long as an over-voltage condition is detected.