Single-stage power supply LED (Light Emitting Diode) constant-current driving PWM (Pulse Width Modulation) input dimming circuit

Abstract

The invention provides a single-stage power supply LED (Light Emitting Diode) constant-current driving PWM (Pulse Width Modulation) input dimming circuit, which comprises an input power supply module, a power supply control module, an isolation power conversion module, a PWM input current adjusting module, a soft starting module, an output switch control module and a constant-current feedback module. The single-stage power supply LED constant-current driving PWM input dimming circuit has the beneficial effects that since the PWM input current adjusting module and the output switch control module are added in a single-stage power supply LED constant-current driving circuit and are matched with the constant-current feedback module and a constant-voltage feedback module, the functions of dimming, turning on / turning off, soft starting, parallel connection of multiple single-stage power supplies of a dual-stage power supply are realized, the problems that the efficiency of a two-stage LED driving PWM dimming circuit is low, the luminous efficiency of an LED lamp is low and the like are solved, the energy saving demands at present are complied, the overall cost of the LED lamp is reduced and the intelligentization of the LED lamp is facilitated.

Description

technical field [0001] The invention relates to the field of LED driving, in particular to a single-stage power supply LED constant current driving PWM input dimming circuit. Background technique [0002] The existing LED dimming power supply circuits are mainly in two forms: [0003] Such as figure 1 , the alternating current AC is converted into a constant direct current DC voltage through a single-stage power supply. The constant direct current DC voltage passes through the step-down circuit again to carry out PWM control circuit output current to dim, turn on, and turn off the LED. [0004] Such as figure 2 , the alternating current AC is converted into a constant direct current DC voltage through a single-stage power supply. The constant direct current DC voltage passes through the step-up circuit again for PWM control circuit output current to dim, turn on, and turn off the LED. [0005] It can be seen that the traditional LED dimming power supply circuit has the...

AI Technical Summary

Problems solved by technology

[0006] 1. The two-stage circuit is used to drive the LED with constant current and PWM dimming, the circuit is complex and costly

[0007] 2. The loss of the two-stage circuit is relatively large, the overall efficiency is relatively low, and the temperature rises

Unfavorable products are energy efficient

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