WLED (White Light Emitting Diode) driving circuit and method suitable for triode-thyristor light modulator

Abstract

The invention discloses a WLED (White Light Emitting Diode) driving circuit and method suitable for a triode-thyristor light modulator. In the driving circuit and method, a novel electronic transformer is provided and can be used for detecting the conduction angle of high-voltage alternating current output by the triode-thyristor light modulator and converting the high-voltage alternating currentinto PWM (Pulse-Width Modulation) low-voltage direct current with a duty cycle regulated by the conduction angle. The PWM low-voltage direct current supplies power to a WLED driver so as to drive a WLED to work; and the triode-thyristor light modulator can be regulated to regulate average current flowing through the WLED so as to change the brightness of the WLED. The PWM low-voltage direct current contains no alternating-current voltage ripples with the frequency of 50Hz and below, and thus, the WLED driving circuit and method suitable for the triode-thyristor light modulator successfully realize the smooth flicker-free light modulation for the WLED.

Description

technical field [0001] The invention relates to a driving method and a driving circuit of an LED, in particular to a driving method and a driving circuit of a triac dimmer suitable for a WLED (white light LED). Background technique [0002] Nowadays, the application of WLED lighting technology has become more and more extensive, and replacing traditional bulb lighting with WLED has become a major trend in the development of WLED lighting technology. However, one of the difficulties in using WLEDs to replace traditional bulb lighting is that the WLED drive circuit must be compatible with standard triac dimmers to adjust the brightness of WLEDs during lighting. service life. [0003] Traditional triac dimmers are designed for purely resistive load lamps, such as incandescent lamps and iodine-tungsten lamps. Because WLEDs do not exhibit resistive load characteristics, it is not possible to achieve good results in dimming WLEDs using traditional triac dimmers. Such as figure...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem of flickering in the dimming process of the existing triac dimmer due to the presence of low-frequency alternating current, and to provide a WLED driving method and drive circuit suitable for the triac dimmer. The driving method and driving circuit can detect the conduction angle of the triac dimmer and apply it to the brightness adjustment of the WLED, thereby realizing wide-range, smooth and flicker-free WLED dimming

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