LED lighting driving circuit and method by using compatible silicon controlled light adjuster to adjust light

Abstract

The invention discloses an LED lighting driving circuit and a method by using a compatible silicon controlled light adjuster to adjust light, an input signal is connected with a silicon controlled light adjusting circuit and a rectifier bridge circuit in series, an output anode of the rectifier bridge circuit is connected with a signal sampling and filtering circuit which is connected with a voltage controlled current source and a loaded LED in series; the output anode of the rectifier bridge circuit is connected with an electric leakage protection circuit; the signal sampling and filtering circuit is characterized in that a normal phase input end of a comparator is connected with the positive end of a benchmark voltage, the negative end of the benchmark voltage is connected to the ground, an output end of the comparator is connected an input end of a phase inverter, the output end of the phase inverter is connected with the input end of a low-pass filter, and the output end of the low-pass filter is connected with a control terminal of the voltage-controlled current source. The LED lighting driving circuit by using the compatible controlled silicon light adjuster to adjust light adopts a silicon controlled electric leakage absorbing circuit to enable the sampled silicon controlled light adjusting signal to be accurate and stable, and the light adjusting effect of the loaded LED is good.

Description

technical field [0001] The invention relates to a dimmable LED driving circuit, in particular to an LED lighting driving circuit compatible with the dimming of a thyristor dimmer and a control method. Background technique [0002] Since the traditional thyristor dimming circuit was originally designed for 40~600W incandescent lamps, and the equivalent model of incandescent lamps is a pure resistance. Therefore, when such a thyristor dimming circuit is directly used in a 3~20W LED drive circuit, the dimmer will work in an abnormal state. [0003] figure 1 It is a schematic diagram of a traditional thyristor dimming circuit. L in the figure is an incandescent lamp. L1 and C1 are filter circuits (mainly absorbing surge voltage and current during circuit switching). Q1 is a bidirectional thyristor. R1, Rw, C2, and D1 form a silicon controlled rectifier opening control circuit. Among them, Rw is an adjustable potentiometer. By changing the resistance value of Rw, the turn-o...

AI Technical Summary

Problems solved by technology

But in fact, due to the presence of leakage current in the thyristor dimming circuit, this will cause the control signal to be unstable, so that the dimming signal cannot be sampled correctly and the dimming cannot be performed. In severe cases, it will cause abnormal phenomena such as flickering of the LED.

Images