Led drive circuit

Abstract

An object of the invention is to provide an LED drive circuit that can suppress the generation of harmonic noise. The LED drive circuit includes a rectifying circuit an LED array, and a current supply circuit which includes a capacitor and a time constant adjusting element, wherein the discharge time constant of the current supply circuit is set longer than the charge time constant of the current supply circuit, and wherein during a period of time when the magnitude of AC commercial power supply voltage is larger than the light emission threshold of the LED array, current to the light-emitting circuit is supplied mostly from the rectifying circuit, and during a period of time when the magnitude of AC commercial power supply voltage is not larger than the light emission threshold of the LED array, current to the light-emitting circuit is supplied from the current supply circuit.

Dependencies are inferred from the claim text.