Circuit for multi-path LED constant current driving

Abstract

The invention discloses a circuit for a multi-path LED constant current driving, comprising a DC / AC converting circuit, a main transformer, a current sharing transformer, a multi-path rectification filter circuit and LED loads, the circuit for the multi-path LED constant current driving is characterized in that: the input direct voltage is converted into alternating voltage by the DC / AC converting circuit, the alternating voltage is isolated by the main transformer and then is input to the current sharing transformer, the current sharing transformer has the function of current sharing for each path of the current, and each path of the current is respectively output to each LED load after passing through each rectification filter circuit. The circuit for the multi-path LED constant current driver has the beneficial effects that: firstly, the balance of load current among multi-path LEDs is realized by a first level converting circuit; secondly, the current sharing control is automatically realized by the current sharing transformer without an extra control circuit, the reliability is high; thirdly, the efficiency of realizing current sharing is high by the current sharing transformer, the loss of realizing current sharing is less when the dropout voltage of two paths of the LEDs is high.

Description

Technical field [0001] The invention relates to a circuit suitable for multi-channel LED constant current driving. Specifically, it should be a way to achieve multi-channel LED load current balance through a current-sharing transformer. 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 regulator module + multi-line adjustment 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 individually controlled for constant current, which can easily ensure the current sharing of the multiple output currents. However, because the voltage of the constant voltage module and the voltage of the LED generally have a ...

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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