LED drive circuit having silicon controlled rectifier regulator, circuit module, and control method

Abstract

The invention discloses an LED drive circuit having a silicon controlled rectifier regulator, a circuit module, and a control method. Before conduction of a silicon controlled rectifier regulator, a direct-current bus voltage is controlled by a bleeder circuit to change in a predetermined manner, so that a phenomenon that conduction points of the silicon controlled rectifier regulators are affected because of inconformity of leakage currents due to different types of the silicon controlled rectifier regulators and different circuit setting and thus a problem of LED scintillation can be solved. Meanwhile, with control of the direct-current bus voltage, the voltage of the silicon controlled rectifier regulator after conduction can be affected, so that the voltage of the conduction point can be set flexibly based on needs.

Description

technical field [0001] The invention relates to power electronics technology, in particular to an LED driving circuit with a thyristor dimmer, a circuit module and a control method. Background technique [0002] Thyristor dimming is a commonly used dimming method at present. The thyristor dimmer adopts the phase control method to realize dimming, that is, the conduction of the thyristor dimmer is controlled in every half cycle of the sine wave, and the same conduction phase angle is obtained. By adjusting the chopping phase of the thyristor dimmer, the conduction phase angle can be changed to realize dimming. [0003] SCR dimmers are usually used to dim incandescent lamps. With the popularity of LED light sources, more and more LED drive circuits use SCR dimmers as dimming means. [0004] In the prior art, TRIAC dimmers are usually used in combination with a linear constant current control scheme. The linear constant current control scheme adjusts the current flowing thro...

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Problems solved by technology

[0005] On the other hand, the thyristor dimmer will have a leakage current before it is turned on. The magnitude of the leakage current is related to the model of the thyristor dimmer and the parameter settings of the LED drive circuit. Different circuit settings and different models can TRIAC dimmers cause variations in leakage current, which in turn causes variations in conduction angle

This uncertainty will lead to the incompatibility of the conduction position and the circuit setting, resulting in the problem of flickering of the LED load

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