Patent ID: 6738245
Filing Date: 2004-05-18
Classification: H02H,H02J,H03K

Abstract:
A series-pass over-voltage protection circuit for supplying operating voltage to a high current electrical load from a DC voltage supply that is subject to transient over-voltage, comprising:a set of parallel-connected transistors coupling said voltage supply to said electrical load; drive control circuitry effective in a normal mode to bias said transistors to a fully conductive state, and in an over-voltage mode to reduce the conduction of said transistors and regulate said operating voltage to a value that will not damage said electrical load; and load sharing means effective during said over-voltage mode for overriding said drive control circuitry by disabling all but a selected one of said transistors, and sequentially indexing the selected transistor so that said transistors are individually enabled in sequence to ensure load sharing among said transistors.