LED DRIVER CIRCUIT FOR SUPPLYING TRIAC HOLDING CURRENT BY USING CONTROLLABLE CURRENT SOURCE

摘要

An LED driver circuit for supplying a TRIAC holding current by using a controllable current source has a single-stage power factor correction circuit architecture, and the circuit receives an input voltage received by a conversion module of the controllable current source to form an operating current for driving an LED light source to emit light and monitoring the change of the input voltage by a control chip, and adopts a switching method of a fixed cut-off time of a switch unit, so that the controllable current source outputs a constant operating current in a standard peak value to achieve the constant current status during the operation of the LED light source while assuring the operating current is always greater than a holding current required by the TRIAC element when the TRIAC element is conducted.