LED stroboflash-free control circuit

Abstract

The invention provides an LED stroboflash-free control circuit. A current mirror composed of M1 and M2 realizes current mirror image. A piezoelectric tube M3 improves a grid control voltage of the current mirror and reduces the mirror image proportion of the current mirror. A current-limiting resistor limits a current on an On circuit. An anti-current-backflow diode D1 prevents the current from flowing backwards into the current mirror. A charging capacitor C1 is used for storing a voltage, and a follow current loop D2 continuously provides a current for an LED lamp. The current mirrored by the current mirror and the current generated by the follow current loop ensure that the controllable gauge dimmer maintains the On state of the circuit, thereby reducing the flicker index. Meanwhile, the circuit also can guarantee that the input current and the input voltage have the same phase, and guarantees that a high power factor exists. The circuit has the advantages of simple circuit structure, obvious stroboscopic effect removal, small chip area, low cost and high power factor.

Description

technical field [0001] The invention relates to the field of LED lamps, in particular to an LED flicker-free control circuit. Background technique [0002] The emergence of LED lamps greatly reduces the power required for lighting. LED lamps with the same wattage require only 1 / 10 of the power required by incandescent lamps. At the same time, LED lamps have the advantages of long life, environmental protection, and maintenance-free, while SCR Dimmers are widely used in traditional lighting markets such as incandescent lamps. They are simple and easy to be used by consumers and conform to people's usage habits. Compatible with TRIAC dimmers. [0003] The dimming mechanism of the thyristor dimmer uses the phase control method to realize voltage regulation or dimming. At a certain moment after the sine wave alternating current crosses zero, a trigger pulse is added to the control electrode of the thyristor to make the thyristor conduct, and this conduction will be maintained ...

AI Technical Summary

Problems solved by technology

It is precisely because the sine wave is cut and the waveform is destroyed, which will cause interference to the power grid and other problems, the LED drive power will produce audio noise and flicker, resulting in the LED light flickering problem in the switch state, and also The power factor (PF) value of the circuit is reduced, and the smaller the conduction angle is, the lower the power factor value is.

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