A linear led drive circuit with replaceable working mode

Abstract

The invention discloses a linear LED drive circuit with replaceable working modes, which relates to a linear LED drive circuit, including a load module, a rectifier module, a dimming reference voltage module, a constant current control module, a first drive module, a second drive module, Dimming mode switch, constant current mode switch, thyristor detection module and working mode control module; the first driving module is used to modulate the output current of the LED load according to the input of the first driving module; the second driving module is used for The external thyristor voltage regulator provides the maintenance current; the thyristor detection module is used to monitor in real time whether there is an external thyristor dimmer; if there is, the working mode control module turns on the dimming mode switch and turns off the constant current mode switch; if No, the working mode control module turns off the dimming mode switch and turns on the constant current mode switch; the present invention can automatically select the working mode according to whether there is an external dimmer, reduce the power consumption of the linear LED drive circuit, reduce the heat dissipation conditions of the linear chip, and reduce the cost .

Description

technical field [0001] The invention relates to a linear LED drive circuit, in particular to a linear LED drive circuit with replaceable working modes. 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 linear high voltage schem...

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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