LED DRIVING CIRCUIT COMPATIBLE WITH SILICON-CONTROLLED DIMMER

摘要

An LED driving circuit compatible with a silicon-controlled dimmer comprises a rectification module (111), a capacitor boosting module (112), a conversion module (115), a voltage sampling module (116), a dummy load module (114), a driving chip (113), and a first switching transistor (M1). The capacitor boosting module (112) comprises at least a first capacitor (CB1) and a second capacitor (CB2). The driving chip (113) is used for providing a latch current to a silicon-controlled dimmer by means of the dummy load module (114) and shutting off the first switching transistor (M1) when a sampled voltage is lower than a preset first threshold, and stopping providing the latch current to the silicon-controlled dimmer and controlling the first switching transistor (M1) to work when the sampled voltage is higher than a preset second threshold, so that a driving voltage is coupled to an LED lamp group by means of the conversion module (115). After being powered on and stabilized, the first capacitor (CB1) charges the second capacitor (CB2) before the silicon-controlled dimmer is turned on. The LED driving circuit improves the compatibility between the silicon-controlled dimmer and the LED driving circuit, and does not generate a large current at the moment when the silicon-controlled dimmer is turned on.