A high voltage linear constant current led drive circuit

Abstract

The invention discloses a high-voltage linear constant-current LED drive circuit, which includes a rectification filter circuit, an LED load group, an operational amplifier power supply circuit, a constant-current control circuit and a PFC adjustment circuit, wherein: the constant-current control circuit uses feedback control to maintain Through the constant current in the LED load group; the PFC adjustment circuit improves the waveform of the input current by adjusting the voltage drop of the LED load group, and improves the power factor; the rectification filter circuit is respectively connected to the operational amplifier power supply circuit, the LED load group and PFC adjustment circuit; the operational amplifier power supply circuit is connected to the constant current control circuit and the PFC adjustment circuit, the constant current control circuit is connected to the LED load group, and the PFC adjustment circuit is connected to the LED load group. The circuit structure of the present invention is simple and reasonable, and realizes the linear constant current function with high PFC, high efficiency and high flexibility through current feedback control and segmental control of lamp beads.

Description

technical field [0001] The invention relates to the field of electronic circuits, in particular to a high-voltage linear constant-current LED driving circuit. Background technique [0002] Due to its high luminous efficiency, low energy consumption, long life, mercury-free and good dimming performance, LEDs are widely used in home lighting and become a new generation of lighting sources. [0003] The lighting method of LED lamps is different from that of traditional lamps. It cannot be directly connected to the AC mains power grid. Instead, it must first convert the AC mains power into a DC power supply through the drive circuit before it can be connected to the LED load. Existing LED drive circuits can be divided into two types: switch-type and linear constant-current LED drive circuits, and the structure of switch-type drive circuits is complex, so the market has begun to use linear constant-current drive circuits that are more conducive to mass production. [0004] The l...

AI Technical Summary

Problems solved by technology

Existing LED drive circuits can be divided into two types: switch-type and linear constant-current LED drive circuits. However, the structure of switch-type drive circuits is complex, so the market is beginning to use linear constant-current drive circuits that are more conducive to mass production.

[0004] The linear constant current drive circuit has the advantages of simple circuit, easy mass production and high efficiency, but it still has some shortcomings. For example, most of the existing linear constant current drive circuits are realized by high-voltage linear constant current IC chips. IC chips are relatively expensive, and their production costs increase accordingly. At the same time, the existing linear constant current drive circuits generally have poor linear adjustment rate, low power factor, and generally cannot achieve dimming, which cannot meet the requirements of LED drive. Due to the high performance and multi-function requirements of the circuit, it is necessary to develop a linear constant current LED drive circuit with low cost, good performance and dimming function.

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