Patent ID: 6529073
Filing Date: 2003-03-04
Classification: H03F

Abstract:
A power supply comprising:a voltage source input; a power converter coupled to the voltage source input, said power converter produces a converted voltage source signal; a switch coupled between the voltage source input and the power converter; a controller coupled to the voltage source input and the switch that opens the switch responsive to detection of a voltage on the voltage source input that exceeds a prescribed limit and that closes the switch responsive to detection of a voltage on the voltage source input that does not exceed the prescribed limit to limit over-voltage transients seen by the power converter; an input voltage sense circuit having a voltage sense input coupled to the voltage source input, the input voltage sense circuit outputs an input voltage signal to the controller; a first voltage sense circuit having a first voltage sense input coupled to the power converter, the first voltage sense circuit outputs a converted voltage signal to the controller; and wherein the controller comprises: a first threshold comparator coupled to the input voltage signal; a second threshold comparator coupled to the converted voltage signal; and a switch drive circuit that opens and closes the switch responsive to the first and second threshold comparators.