Patent ID: 6606228
Filing Date: 2003-08-12
Classification: H01H

Abstract:
A fault detection circuit, comprising:an input voltage coupled to an output load through a control switch; a control signal regulating the conduction state of said control switch; and fault detection circuitry receiving said control signal and a signal indicative of the energy delivered to said load, and adapted to determine if said control switch is in the proper conduction state based on said control signal, said fault detection circuit further adapted to decouple said input voltage from said load using said energy delivered to said output load if said control switch is in an improper conduction state; further comprising control circuitry generating a second control signal to decouple from said load when said control switch is in aid improper conduction state; wherein said fault detection circuitry comprises fuse circuitry coupled to a second switch, said fuse circuitry being disposed between said input voltage and said load, and wherein said control circuitry receives said control signal and said signal indicative of the energy delivered to said load and generates said second control signal to control the conduction state of said second switch, wherein if said control switch is in an improper conduction state, said second switch diverts energy at said load through said fuse circuitry thereby decoupling said load from said input voltage; and wherein said control circuitry includes an inverter receiving said control signal and generating an inverted control signal, and an AND gate receiving said inverted control signal and said signal indicative of the energy delivered to said load and generating said second control signal.