Patent ID: 8988002
Filing Date: 2015-03-24
Classification: H05B,Y02B

Abstract:
1. A lighting power supply device which receives a voltage converted from an alternating current to a direct current by a rectifying circuit rectifying the alternating current whose phase is controlled by a phase control type dimmer, and generates and outputs a direct current voltage/current to be supplied to a load, the lighting power supply device comprising: a control circuit, which gradually decreases a current drawn from the rectifying circuit from a predetermined current value set in advance, determines a current value immediately before detecting a malfunction of the phase control type dimmer as a drawn current value, and performs current control so as to maintain the determined current value; wherein the control circuit includes: a timing detection circuit which detects a zero-cross timing at which the voltage input to the control circuit becomes zero and an edge timing at which the input voltage rapidly changes; a malfunction determination circuit which determines the malfunction of the phase control type dimmer, when the zero-cross timing has not been detected and the edge timing has been detected a predetermined number of times, based on detection results provided by the timing detection circuit.