Impulse light-regulation circuit and impulse light-regulation method

Abstract

The present invention provides a pulse dimming circuit and a method thereof. The pulse dimming circuit is compatible for both DC input signal and PWM input signal using only one circuit board, and includes a first input port, a second input port, a comparison signal generator, a comparator, a logic module, and a switch network electrically coupled to the second input port, an output terminal of the comparator, and an output terminal of the logic module.

Description

technical field [0001] The invention relates to a dimming circuit and a method thereof for a cold cathode fluorescent lamp, in particular to a pulse dimming circuit and a pulse dimming method. Background technique [0002] The inverter of cathode fluorescent lamp (CCFL) often adopts pulse dimming, and there are usually two pulse dimming methods, that is, pulse dimming using DC input voltage and pulse dimming using external PWM input signal. For the pulse dimming method of DC input, it is necessary to compare the wave generator component, and generate the pulse signal for pulse dimming by comparing the DC input level with the comparative wave; and for the pulse dimming method using PWM input signal That said, the pulse dimming signal directly follows the PWM input signal, so no comparator wave generator components are required. Therefore, the two pulse dimming methods are not compatible with each other. Circuits for pulse dimming with DC input are not suitable for pulse dim...

AI Technical Summary

Problems solved by technology

The current solution often uses two circuit boards, each for a dimming method, but this is costly and inconvenient

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