LED (light emitting diode) street lamp driving circuit capable of regulating output illuminance automatically

Abstract

The invention belongs to the technical field of electronics, and relates to an LED (light emitting diode) street lamp driving circuit capable of regulating output illuminance automatically. The driving circuit comprises an input surge protection and electromagnetic interference suppression circuit, a single-tube flyback switch power circuit with a power factor correction function, an environment illuminance detection circuit, a chip temperature detection circuit, a perpetual calendar chip, the periphery circuit of the calendar chip and an output current automatic regulation switch circuit controlled by a microcomputer; a dual-control working mode with the primary light control and auxiliary time control by the microcomputer for a general switch control module provided by the invention; and when the primary control is out of control, the auxiliary control replaces working automatically, and the light control according to the set illuminance controls the starting and closing operation of the street lamp. The driving circuit provided by the invention has the advantages of power factor correction, can regulate the output current automatically according to time, the environment illuminance and the LED chip temperature, can control the luminosity to regulate the output current directly as the control mode, and compared with the traditional low-frequency PWM (pulse width modulation) control method, the electromagnetic interference is less, and is more friendly to human eyes.

Description

technical field [0001] The invention belongs to the field of electronic technology, and relates to an LED street lamp driving circuit for automatically adjusting output brightness. In particular, it relates to an LED street lamp driving circuit which can automatically adjust output brightness according to time, ambient brightness and LED chip temperature. Background technique [0002] LED lighting is directly converted from electric energy to light energy, with high efficiency and high effective lumens. Generally, a 120W LED street lamp is equivalent to the illuminance of a 400W traditional high-pressure sodium lamp, which can save a lot of energy. On the other hand, LED light sources have the advantages of long life, maintenance-free, easy dimming and intelligent control, no mercury, lead and other harmful substances, no pollution and environmental protection, etc. The use of LED lighting can reduce carbon dioxide, sulfur dioxide and other polluting waste gas by 300 million...

AI Technical Summary

Problems solved by technology

[0004] The conventional constant current drive circuit cannot adaptively adjust the output brightness according to the change of ambient light

In addition, LED working for a long time will cause the junction temperature of the chip to rise, and the effective life of the LED and the output luminous flux are inversely proportional to the junction temperature.

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