A LED drive circuit that regulates the current in a full range and corrects the dimming curve

Abstract

The present invention relates to an LED drive circuit for adjusting current in a full range and correcting dimming curve, including a filter circuit 1, a signal processing circuit, and an LED constant current drive circuit, characterized in that the signal processing circuit includes a voltage reference circuit, a filter circuit 2 and The dimming curve correction circuit; the LED constant current drive circuit includes a delay start circuit, a DC / DC conversion circuit, a feedback circuit and a filter circuit 3 . The advantages of the present invention are: full hardware analog circuit, simple circuit structure, adjustable output current, achievable dimming range of 1% to 100%, conforming to visual man-machine effect, good electromagnetic compatibility, and resistant to various environments and climates Etc. It can be popularized and applied in lighting fields of various fields and industries.

Description

technical field [0001] The patent of the present invention relates to an LED constant current drive circuit, especially an LED drive circuit that regulates the current in a full range and corrects the dimming curve. Background technique [0002] At present, LED lamps with dimming function are widely used in various types of aircraft. There are two commonly used LED dimming driving methods: voltage dimming and PWM dimming. Voltage dimming is to adjust the brightness by changing the voltage at both ends of the LED, but the dimming range is small, and the brightness consistency is poor when dimming multiple lamps; because the current rises after the LED heats up, the reliability of the LED is affected, and it is only suitable for small power and heat generation. Small light fixtures. PWM dimming adjusts the brightness by controlling the on-off ratio of the LED under constant current, which has high efficiency and high dimming accuracy, but only the single-chip microcomputer a...

AI Technical Summary

Problems solved by technology

Voltage dimming is to adjust the brightness by changing the voltage at both ends of the LED, but the dimming range is small, and the brightness consistency is poor when dimming multiple lamps; because the current rises after the LED heats up, the reliability of the LED is affected, and it is only suitable for small power and heat generation. small lamps

PWM dimming adjusts the brightness by controlling the on-off ratio of the LED under constant current, which has high efficiency and high dimming accuracy, but only the single-chip microcomputer and software can achieve stable 1% to 100% wide-range brightness adjustment and uniform dimming The human-machine effect, the circuit is relatively complex, and the volume is large. It is generally used for large-scale lamps. The PWM dimming frequency is between 200 and 20kHz. The electromagnetic interference generated by the low-frequency band cannot meet the electromagnetic compatibility requirements of all military platform aircraft.

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