Patent ID: 7804195
Filing Date: 2010-09-28
Classification: H02J

Abstract:
1. A power supply system for an electronic device comprising: a first connector for connecting to a first power source; a second connector for connecting to a second power source, wherein the second power source is rechargeable; a switch for establishing a connection between the first connector and the second connector so as to allow the first power source to charge the second power source, wherein the switch comprising a bipolar junction transistor with the base connected to the controller through a resistor, the collector being connected to the first connector through a resistor, and the emitter connecting to ground; and an insulated gate bipolar transistor with the source connecting to the first connector, the drain connecting to the second connector, and the gate connecting to the collector of the bipolar junction transistor; and a controller for detecting a presence of the first power source and the second power source, and controlling the bipolar junction transistor and the insulated gate bipolar transistor of the switch to periodically establish the connection at the absence of the second power source, and to continuously establish the connection at the presence of the second power source.