Patent ID: 7723869
Filing Date: 2010-05-25
Classification: H02M,H03K

Abstract:
1. A device for controlling a JFET power electronic switch of normally ON type, the control device comprising: a main gate control circuit powered by a main power source for driving the gate of the JFET switch; a protection switching device that is switchable between first and second positions; an auxiliary control circuit driving the protection switching device; an auxiliary power source that is supplied by the main power source, whose positive terminal is connected to the source of the JFET switch and whose negative terminal is connected to the gate of the JFET switch bypassing the main gate control circuit in the second position of the protection switching device, the auxiliary control circuit controlling the protection switching device such that when power from the main power source to the auxiliary control circuit falls below a threshold, the protection switching device is put in the second position.