Patent ID: 7332833
Filing Date: 2008-02-19
Classification: H02J

Abstract:
1. A switching circuit for a master-slave feeding mode of the low voltage power supply, wherein said switching circuit comprising: a master power supply input terminal, a secondary power supply input terminal, an output terminal; a master switch between master input terminal and output terminal, a secondary switch between slave power supply input terminal and output terminal; a sampling device for sampling signals from said master input terminal and slave input terminal; a control device for judging and controlling “on” or “off” states of said master and slave switches according to output of said sampling device, wherein when power supply input at the master power supply input terminal is normal, said control device controls the master switch to be “on”, and the secondary switch to be “off”; and when said power supply input at the master power supply input terminal is not normal said control device controls the master switch to be “off”, and the secondary switch to be “on”, wherein said control device comprises a dual-comparer constituted by two comparers, and an output terminal of a first comparer is connected to one of at least two input terminals of a second comparer.