Patent ID: 7709975
Filing Date: 2010-05-04
Classification: H02J

Abstract:
1. A redundant power supply system comprising: a first power supply; a second power supply; a first sensor connected to the first power supply; a control circuit comprising a first input terminal connected to the first sensor to receive a status signal of the first power supply, a first NOT gate having an input terminal connected to the first input terminal, and acting as a first output terminal of the control circuit to send a first control signal, and a delay circuit having an input terminal connected to an output terminal of the first NOT gate, and an output terminal acting as a second output terminal of the control circuit to send a second control signal; and a relay switch configured to receive the two control signals from the two output terminals of the control circuit, and select the first power supply or the second power supply to supply power to an electronic device according to the two control signals; wherein the relay switch comprises a first solid state relay, a second solid state relay, a third solid state relay, and a fourth solid state relay, each solid state relay has a first input terminal, a second input terminal, a first output terminal, and a second output terminal, the first input terminals of the first solid state relay and the second solid state relay are coupled to a live wire and a neutral wire of the first power supply respectively, the first input terminals of the third solid state relay and the fourth solid state relay are coupled to a live wire and a neutral wire of the second power supply respectively, the second input terminals of the first solid state relay and the second solid state relay are coupled to the first output terminal of the control circuit, the second input terminals of the third solid state relay and the fourth solid state relay are coupled to the second output terminal of the control circuit, the first output terminals of the first solid state relay and the third solid state relay are coupled to a first output terminal of the relay switch, the first output terminals of the second solid state relay and the fourth solid state relay are coupled to a second output terminal of the relay switch, all the second output terminals of the solid state relays are grounded, the first output terminal and the second output terminal of the relay switch are coupled to the electronic device.