Patent ID: 8704457

Claim:
A power conversion circuit for light emitting diode, adapted to drive a light emitting diode string, the power conversion circuit comprising: a voltage converter, having two receiving terminals and two output terminals, the two receiving terminals being electrically coupled to a direct current power supply to convert the direct current power supply to direct current output signals which are outputted from the output terminals of the voltage converter to drive the light emitting diode string, wherein one of the output terminals has a positive potential and another one of the output terminals has a negative potential; wherein the voltage converter comprises: a first receiving terminal electrically coupled to a high potential of the direct current power supply; a second receiving terminal electrically coupled to a low potential of the direct current power supply; a first output terminal configured for providing an output of positive potential; a second output terminal configured for providing an output of negative potential; a switch having a first terminal and a second terminal, the first terminal of the switch being electrically coupled to the first receiving terminal; a first inductor having a positive terminal and a negative terminal, the positive terminal of the first inductor being electrically coupled to the second terminal of the switch, the negative terminal of the first inductor being electrically coupled to the second receiving terminal; a second inductor having a positive terminal and a negative terminal, the second inductor being electromagnetically coupled to the first inductor, and the negative terminal of the second inductor being maintained at a preset low potential; a third inductor having a positive terminal and a negative terminal, the third inductor being electromagnetically coupled to the first inductor, and the negative terminal of the third inductor being electrically coupled to the second output terminal; a first unilateral connecting component electrically coupled to the positive terminal of the second inductor and the first output terminal, and only allowing electrical current to flow from the positive terminal of the second inductor to the first output terminal; a second unilateral connecting component electrically coupled to the positive terminal of the third inductor and the negative terminal of the second inductor, and only allowing electrical current to flow from the positive terminal of the third inductor to the negative terminal of the second inductor; a first capacitor, one end of the first capacitor being electrically coupled to the first output terminal, and another end of the first capacitor being electrically coupled to the negative terminal of the second inductor; and a second capacitor, one end of the second capacitor being electrically coupled to the negative terminal of the second inductor, and another end of the second capacitor being electrically coupled to the second output terminal.