Silicon-controlled dimmer detection circuit for linear LED driving

Abstract

The invention discloses a silicon-controlled dimmer detection circuit for linear LED driving, and relates to the technical field of linear LED driving. The silicon-controlled dimmer detection circuitcomprises a valley detection unit, a dimmer detection unit, a charging control unit and a mode control unit, wherein the valley detection unit is used for detecting a valley of an input rectificationvoltage, the dimmer detection unit is used for judging whether valley time of the input rectification voltage conforms to a condition with presence of a dimmer or not by change of a voltage of a non-grounding end of a detection capacitor, the charging control unit is used for controlling the detection capacitor to charge and discharge by judging whether the input rectification voltage is at the valley or not, and the mode control unit is used for receiving a detection pulse signal of the dimmer and controlling a working mode of the LED driving circuit according to whether the input rectification voltage is at the valley or not. By the silicon-controlled dimmer detection circuit, whether an external dimmer exists or not can be detected, so that the system can select a corresponding workingmode, the power consumption of the linear LED driving circuit is reduced, the cooling condition of a linear chip is reduced, and the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of linear LED drive, in particular to a silicon controlled dimmer detection circuit for linear LED drive. Background technique [0002] Nowadays, due to the rapid development of LED lighting, the original tens of watts of incandescent lamps can be directly replaced by LED bulb lamps of several watts, which can save a lot of energy. Since the traditional incandescent lamp is a purely resistive load, it is usually directly used for phase-cut angle dimming with a thyristor dimmer. Since traditional incandescent lamps are usually tens to hundreds of watts, the design of the silicon controlled rectifier dimmer is designed for this load. However, if this kind of thyristor dimmer is used to directly dim a few watts of LED lamps, since the LED lamps are not purely resistive loads, it will cause serious flickering and other problems. According to the load characteristics of the LED, a switch dimming scheme or a lin...

AI Technical Summary

Problems solved by technology

When it is necessary to be compatible with solutions with and without TRIAC dimmers at the same time, the existence of the maintenance current will cause the traditional dimming schemes to generally have low efficiency without dimmers, which will inevitably lead to the need to increase the linear chip Heat dissipation conditions, increased costs, and some hard indicators that cannot meet the light efficiency

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