| 摘要 |
PROBLEM TO BE SOLVED: To enhance the efficiency of a constant-current power supply apparatus, capable of carrying out constant-current control, even under light load. SOLUTION: The constant-current power supply apparatus 1 includes a first primary winding T1 of a transformer T connected in series with the cathode of the light-emitting diode LEDn of multiple light-emitting diodes LED1 to LEDn connected in series, a second primary winding T2 of the transformer T connected in series with the first primary winding T1 of the transformer T through a tap A, a switch element Q1 connected in series with the second primary winding T2 of the transformer T, a diode D1 whose anode is connected with the tap A and whose cathode is connected with the anode of the light-emitting diode LED1, a control unit 21 that controls the switch element Q1, and a snubber circuit 31 connected to the tap A. COPYRIGHT: (C)2011,JPO&INPIT
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