초록 ▼

An exemplary dual power supply system includes a first sensor connected to a first power supply, a second sensor connected to a second power supply, a selection switch, a control circuit, and a relay switch. Each of the output terminals of the first sensor, the second sensor, and the selection switc

An exemplary dual power supply system includes a first sensor connected to a first power supply, a second sensor connected to a second power supply, a selection switch, a control circuit, and a relay switch. Each of the output terminals of the first sensor, the second sensor, and the selection switch are connected to a corresponding input terminal of the control circuit. The first and the second power supplies are connected to an electronic device via the relay switch. A control terminal of the relay switch is coupled to an output terminal of the control circuit for selectively coupling the first or the second power supply to the electronic device according to a control signal generated by the control circuit.

대표청구항 ▼

What is claimed is: 1. A dual power supply system comprising: a first sensor having a detecting terminal connected to a first power supply and an output terminal to send a first power signal; a second sensor having a detecting terminal connected to a second power supply and an output terminal to se

What is claimed is: 1. A dual power supply system comprising: a first sensor having a detecting terminal connected to a first power supply and an output terminal to send a first power signal; a second sensor having a detecting terminal connected to a second power supply and an output terminal to send a second power signal; a selection switch having an output terminal to send a selection signal; a control circuit having three input terminals connected to the output terminals of the first sensor, the second sensor, and the selection switch respectively, and an output terminal to send a control signal according to the first power signal, the second power signal, and the selection signal; and a relay switch having two throws connected to the first and the second power supplies respectively, a pole connected to an electronic device, and a control terminal connected to the output terminal of the control circuit for selectively coupling the pole to one of the throws thereby coupling the first or second power supply to the electronic device according to the control signal; wherein upon a condition that one of the first and second power supplies does not work, the control signal is controlled by the first and second power signals and causes the relay switch to couple the other one of the first and second power supplies to the electronic device; upon a condition that the first and second power supplies both work normally, the control signal is controlled by the selection signal and causes the relay switch to couple a selected power supply of the first and second power supplies to the electronic device; the control circuit includes a NOT gate, an OR gate, and an AND gate, two input terminals of the OR gate are connected to the output terminal the second sensor via the NOT gate and the output terminal of the selection switch respectively, the output terminal of the OR gate and the output terminal of the first sensor are connected to two input terminals of the AND gate respectively, an output terminal of the AND gate acting as the output terminal of the control circuit is connected to the relay switch. 2. The dual power supply system as claimed in claim 1, wherein the relay switch has a first channel having a normally open throw connected to a live wire of the first power supply and a normally closed throw connected to a live wire of the second power supply, a second channel having a normally open throw connected to a naught wire of the first power supply and a normally closed throw connected to a naught wire of the second power supply, and a relay to control the first and the second channels according to the control signal. 3. The dual power supply system as claimed in claim 1, wherein each of the first and second sensors is a voltage sensor. 4. A dual power supply system comprising: a main power supply end a backup power supply; a control circuit comprising a first input terminal connected to the main power supply via a first sensor and configured to receive a status signal of the main power supply from the first sensor, a second input terminal connected to the backup power supply via a second sensor and configured to receive a status signal of the backup power supply from the second sensor, a third input terminal connected to a selection switch for receiving a selection signal from the selection switch, and an output terminal to output a control signal, the control signal being achieved by arithmetic performed on the statue signals of the main and backup power supplies and the selection signal; and a relay switch configured to receive the control signal from the output terminal of the control circuit, and select the main power supply or the backup power supply to supply power to an electronic device according to the control signal; wherein upon a condition that one of the main and backup power supplies does not work, the control signal is controlled by the status signals of the main and backup power supplies and causes the relay switch to couple the other one of the main and backup power supplies to the electronic device; upon a condition that the main and backup power supplies both work normally, the control signal is controlled by the selection signal and causes the relay switch to couple a selected power supply of the main and backup power supplies to the electronic device; the control circuit further comprises a NOT gate, an OR gate, and an AND gate, the first input terminal is connected to one of two inputs of the AND gate, the second input terminal is connected to one of two inputs of the OR gate via the NOT gate, the third input terminal is connected to the other one of the two inputs of the OR gate, an output of the OR gate is connected to the other one of the two inputs of the AND gate, an output of the AND gate acts as the output terminal of the control circuit. 5. The dual power supply system as claimed in claim 4, wherein the relay switch has a first channel having a normally open throw connected to a live wire of the first power supply and a normally closed throw connected to a live wire of the second power supply, a second channel having a normally open throw connected to a naught wire of the first power supply and a normally closed throw connected to a naught wire of the second power supply, and a relay coupled to the output terminal of the control circuit and configured to control the first and the second channels according to the control signal. 6. The dual power supply system as claimed in claim 4, wherein each of the first and second sensors is a voltage sensor. 7. A dual power supply system comprising: a first power supply and a second power supply; a control circuit comprising a plurality of logical gates, a first input terminal connected to the first power supply via a first sensor and configured to receive a status signal of the first power supply from the first sensor, a second input terminal connected to the second power supply via a second sensor and configured to receive a status signal of the second power supply from the second sensor, a third input terminal connected to a selection switch for receiving a selection signal therefrom, and an output terminal configured to output a control signal achieved by arithmetic performed on the status signals of the power supplies and the selection signal by the gates; and a relay switch having two throws connected to the first and the second power supplies respectively, a pole connected to an electronic device, and a control terminal connected to the output terminal of the control circuit for selectively coupling the pole to one of the throws thereby coupling the first or second power supply to the electronic device according to the control signal; wherein upon a condition that one of the first and second power supplies does not work, the control signal is controlled by the status signals of the first and the second power supplies and causes the relay switch to couple the other one of the first and second power supplies to the electronic device; upon a condition that the first and second power supplies both work normally, the control signal is controlled by the selection signal and causes the relay switch to couple a selected power supply of the first and second power supplies to the electronic device; the gates comprises a NOT gate, an OR gate, and an AND gate, the first input terminal is connected to one of two inputs of the AND gate, the second input terminal is connected to one of two inputs of the OR gate via the NOT gate, the third input terminal is connected to the other one of the two inputs of the OR gate, an output of the OR gate is connected to the other one of the two inputs of the AND gate, an output of the AND gate acts as the output terminal of the control circuit. 8. The dual power supply system as claimed in claim 7, wherein the relay switch has a first channel having a normally open throw connected to a live wire of the first power supply and a normally closed throw connected to a live wire of the second power supply, a second channel having a normally open throw connected to a naught wire of the first power supply and a normally closed throw connected to a naught wire of the second power supply, and a relay coupled to the output terminal of the control circuit and configured to control the first and the second channels according to the control signal. 9. The dual power supply system as claimed in claim 7, wherein each of the first and second sensors is a voltage sensor.