Patent ID: 6118641
Filing Date: 2000-09-12
Classification: H02H

Abstract:
A two terminal circuit protection arrangement which:(1) is intended to be series connected in a line of a circuit to be protected;(2) comprises:(a) a series switching transistor whichi. is selected from bipolar transistors and field effect transistors and(i) if it is a bipolar transistor, comprises a collector, an emitter and a base, and(ii) if it is a field effect transistor, comprises a drain, a source and a gate, andii. controls the line current;(b) a voltage divider which is connected to the source and drain or to the emitter and collector of the switching transistor, and(c) a control transistor whichi. is selected from bipolar transistors and field effect transistors, and(i) if it is a bipolar transistor, comprises a collector, an emitter and a base, and(ii) if it is a field effect transistor, comprises a drain, a source and a gate,ii. has its base or gate voltage determined by the voltage divider,iii. controls the base or gate voltage of the switching transistor, andiv. is turned on by a voltage across the collector and emitter or source and drain of the switching transistor resulting from an overcurrent through the switching transistor, thereby causing the switching transistor to put the arrangement in a non-conducting state, and(d) a voltage source which is applied to the base or gate of the switching transistor and which biases the switching transistor into or toward conduction in normal operation; and(3) is capable of being reset from the non-conducting state into a conducting state by a remotely controlled interrupting means which interrupts current in the line of the circuit to be protected.