Patent ID: 8816597
Filing Date: 2014-08-26
Classification: H05B,Y02B

Abstract:
1. An LED driving circuit for driving an LED, the circuit comprising: a dimming circuit that controls a conducting angle of an alternating current supplied from a commercial alternating-current power supply so as to phase-control a current to be supplied to the LED; a rectifier circuit that rectifies an alternating-current voltage output from the dimming circuit; a smoothing circuit that smoothes a direct current voltage output from the rectifier circuit; a switching device that is connected with the LED in series; a constant current control circuit that outputs a pulse signal to the switching device to control an ON/OFF operation of the switching device so that a current flowing in the LED becomes constant; and a bleeder circuit that is provided between an output terminal of the rectifier circuit and a ground and that has a bleeder resistance and a bleeder switch which are connected with each other in series, wherein the pulse signal which is input to the switching device, is also input to the bleeder switch and a bleeder current having a pulse form flows in the bleeder resistance, and the bleeder current pulse is overlapped to a dimming current output from the dimming circuit.