Light-adjustable light-emitting diode (LED) drive circuit

Abstract

The invention relates to a light-adjustable light-emitting diode (LED) drive circuit. The light-adjustable LED drive circuit is strong in anti-electromagnetic interference, high in power factor and high in reliability. The light-adjustable LED drive circuit comprises an anti-electromagnetic interference unit used for filtering external electromagnetic interference, a power factor correction unit used for improving the power factors of a power supply, a bridge rectifier circuit used for converting alternating current electric energy into direct current electric energy, a light modulator used for modulating voltage input into a voltage transformation rectifying circuit, a drive unit used for supplying electric energy to the light modulator, a voltage transformation rectifying circuit providing work current for an an LED light-source unit, a feedback circuit used for feeding back the work voltage of the voltage transformation rectifying circuit to a switch control circuit, the switch control circuit used for controlling output current of the voltage transformation rectifying circuit, and the LED light-source unit.

Description

technical field [0001] The invention relates to the field of LED lighting, in particular to a dimmable LED driving circuit. Background technique [0002] LED has many unique advantages, such as high luminous efficiency, low power consumption, long life, high stability, pure light color, good safety and strong controllability. , fluorescent lamps, and high-intensity gas discharge lamps are the fourth generation of light sources. The application field of LED is very broad. It can be used in the backlight market, automobile lamp market, interior decoration lamp market, landscape lighting market and general lighting market, etc., and has become the mainstream of today's light source. Although LED technology is constantly developing, there are still many problems in the field of LED technology that prevent it from being widely popularized. [0003] In order to achieve the purpose of automatically dimming LEDs, people often use timers or photosensitive sensors to achieve automat...

AI Technical Summary

Problems solved by technology

This technical solution mainly realizes LED circuit on-off and dimming according to specific conditions, and the control is single and difficult, and it is impossible to realize intelligent control in the true sense.

In order to enable LED to realize intelligent lighting according to environmental changes, user predetermined needs, centralized and unified control and other conditions, people mainly continuously test and improve the control conditions, parameters or hardware of LED circuits, but they do not provide power factor correction and electromagnetic compatibility. The circuit makes the high-order harmonics generated by the LED during operation cause harmonic pollution and interference to the power grid and other electrical appliances, and also makes the LED itself less capable of resisting external electromagnetic interference

[0004] In addition, the current LED lighting system usually uses AC switching power supply to provide constant current drive. This kind of drive circuit will have the following disadvantages: low power conversion factor; The brightness change of the LED is not obvious, and the brightness changes greatly when the knob angle is turned to the minimum, resulting in a poor dimming feel; the compatibility between the power supply and the dimmer is poor, and even the phenomenon of non-dimming occurs, that is, the brightness change is small; controllable Silicon dimmers have a large current impact, resulting in circuit instability and low reliability

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