Dimmable light-emitting diode (LED) driving power supply

Abstract

The invention provides a dimmable light-emitting diode (LED) driving power supply, comprising an electromagnetic-interference resisting unit, a rectifying unit, a current transforming unit, a silicon-controlled unit, a dimming unit and a strobing resisting unit. The strobing resisting unit comprises two diodes, a resistance-capacitance network, a voltage follower, a transistor and a field-effect transistor; the anodes of the two diodes are connected with the silicon-controlled unit, and the cathodes of the two diodes are connected with the drain electrode of the field-effect transistor and are also connected with one input end of the voltage follower through the resistance-capacitance network; the other input end of the voltage follower is connected with the output ends of the diodes; the source electrode of the field-effect transistor is connected with the collector electrode of the triode through the resistance, and the collector of the triode is connected with the ground; signals output by the voltage follower are used for controlling the work state of the triode; and when the conduction angle of the field-effect transistor decreases and is in the wave trough, the triode is fully conducted with the field-effect transistor to maintain the conduction current of the silicon-controlled unit, thereby ensuring the silicon-controlled unit to be in the conduction state and preventing the silicon-controlled unit from being conducted repeatedly to strobe.

Description

technical field [0001] The invention relates to an LED driving power supply, in particular to a dimmable LED driving power supply. Background technique [0002] LED (Light Emitting Diode) has the advantages of low power consumption, long service life, and low cost. It is widely used in lighting, display and other fields, such as LED lighting, LED display screen, LED lighting and so on. [0003] The power of traditional dimmers is relatively large (200W ~ 600W), and the thyristor needs a certain holding current to maintain its conduction. However, in low-power LED driving applications, it is generally impossible to ensure that there is a large enough input current to maintain controllability. Silicon works stably. In this way, multiple conductions may occur, so the voltage and related signals supplied to the LED driver will be unstable. If the dimming signal is not handled properly, the LED will flicker. Contents of the invention [0004] The purpose of the present invent...

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Problems solved by technology

[0003] The power of traditional dimmers is relatively large (200W ~ 600W), and the thyristor needs a certain holding current to maintain its conduction. However, in low-power LED driving applications, it is generally impossible to ensure that there is a large enough input current to maintain controllability. Silicon stable work

In this way, there may be multiple conductions, so the voltage and related signals supplied to the LED driver will be unstable. If the dimming signal is not handled properly, the LED will flicker

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