LED constant current driving circuit

Abstract

The invention relates to an LED constant current driving circuit comprising LED load, a power supply, and also at least one constant current chip, a main control circuit and a switching circuit, wherein the at least one constant current chip is electrically connected with the LED load and used for conducting constant current regulation on the LED load, the main control circuit is connected with the power supply and used for conducting pulse width modulation according to input signals of the constant current chip and outputting control signals, and the switching circuit is electrically connected between the control signal outputting end of the main control circuit and the LED load. The LED constant current driving circuit has the advantages of capability of supplying adjustable constant current value, high constant current accuracy, high efficiency, high circuit reliability, simple circuit and low cost.

Description

technical field [0001] The present invention relates to a driving circuit, more specifically, to an LED constant current driving circuit. Background technique [0002] Today, as a new generation of light sources, LEDs are used in a wider range of applications. However, LEDs generally require a constant driving current, and a slight instability of the current at both ends of the LED will cause flickering of the light emitted by the LED. At present, the low-voltage isolation-free high-power LED constant current drive circuit generally adopts the following two methods: [0003] 1. Use a buck circuit (buck) or a boost circuit (boost) or a pulse width modulation control (PWM, Pulse Width Modulator) LED constant current drive circuit combining buck and boost. In this way, the electrical signal output by the LED load is fed back to the main control unit (MCU, Micro Controller Unit), and then the internal program algorithm of the MCU is used for PWM modulation to achieve the effec...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a constant current with high precision, adjustable constant current value, high reliability, simple circuit and low cost for the defects of the above-mentioned constant current circuit in the prior art. Low LED constant current drive circuit

Images