Drive circuit for realizing accurate constant current of multiple LEDs

Abstract

The invention discloses a drive circuit for realizing the accurate constant current of multiple LEDs, which comprises a high-frequency impulse alternating current power supply, a rectification filter circuit, a blocking condenser C1 and two ways of LED loads, and is characterized in that the rectification filter circuit comprises two independent half-wave rectifying circuits, a filter capacitor C2 and a filter capacitor C3; and the two independent half-wave rectifying circuits respectively supply power for the two ways of LED loads, the filter capacitor C2 and the filter capacitor C3 are respectively connected on the two ends of the two ways of LED loads in parallel, and the blocking condenser C1 is connected with the input end of the rectification filter circuit in series. The invention has the following beneficial effects that: 1, a first class transformation circuit is adopted to realize the uniform current of the loads between multiple LEDs, the cost is low, additional control circuits do not needed, and the reliability is high; 2, the uniform current has high accuracy and cannot be influenced by the differential pressure of the LED loads; and 3, the blocking condenser can realize high efficiency of the uniform current, i.e. when the differential pressure of the two ways of LEDs is larger, the loss to realize uniform current is smaller.

Description

technical field [0001] The invention relates to a driving circuit for realizing accurate constant current of multiple LEDs. Specifically, it should be a circuit that balances the LED load current through a DC blocking capacitor. Background technique [0002] For the application of LED multi-channel constant current control driver, the most commonly used solutions are: 1. Constant voltage module + multi-channel non-isolated DC / DC constant current circuit (such as BUCK circuit); 2. Voltage adjustable voltage regulator module + multi-line Sexually adjust the constant current circuit. [0003] For the first option, refer to figure 1 , the output of the constant voltage module is used as the input of multiple constant current circuits, and each constant current circuit is independently controlled by constant current, which can easily ensure the current sharing of multiple output currents. However, because the voltage of the constant voltage module and the voltage of the LED ge...

AI Technical Summary

Problems solved by technology

Although the circuit cost of this solution is low and the current sharing of each LED is good, short circuit is a common failure mode of LEDs. When the voltage difference of multiple LEDs is relatively large, the power consumption of the linear adjustment tube is very large, which makes the LED driver seriously heat.

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