Constant current control method and circuit of multipath paralleled LED power supply

Abstract

The invention discloses a constant current control method and a circuit of a multipath paralleled LED power supply. The method comprises the following steps: S100: presetting a current threshold and an MOS (Metal Oxide Semiconductor) voltage drop threshold; S110: opening an MOS tube; S200: detecting the current of each LED lamp bank, judging whether a current value is less than the threshold exists or not, if so, executing S300; and otherwise, executing S400; S300: controlling an AC-DC module to boost the LED lamp banks by using an optical coupling feedback control circuit to ensure that current values of all LED lamp banks are greater than the set current threshold; S400: carrying out current drop processing on the LED lamp banks the current values of which are greater than the set threshold by using a control module to ensure that the current value of each LED lamp bank is equal to the preset current threshold; and S500: carrying out voltage drop detection on the MOS tube of each LED lamp bank by using the control module, controlling the AC-DC module to reduce the direct current output voltage of the MOS tube the voltage drop of which is greater than the threshold and then executing the S200. By adopting the invention, the problems of the light equation and the light decay can be effectively solved and the efficiency of the circuit can be greatly improved.

Description

technical field [0001] The invention relates to a constant current control technology for multi-channel parallel connection of LED power sources, in particular to a multi-channel parallel constant current control method and circuit for LED power sources. Background technique [0002] When the existing LED power supply is connected in parallel, firstly, the mains power is converted into DC output through the AC / DC power supply module (AC to DC power supply) as the power supply of the LED lamp. At present, one of the circuit design schemes is as follows: figure 1 As shown, this solution is to directly connect multiple sets of LED lamps in parallel at the output end of the AC / DC power module. This method will lead to inconsistent currents on each group of LED lamp groups due to differences between LED individuals, which will lead to light difference between LED lamp groups and directly affect the effect of LED lights; in addition, the light decay of LED lights is very serious. ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a multi-channel parallel LED power supply constant current control method and circuit, aiming to solve the problem of light difference and light attenuation caused by current imbalance between the existing LED power supply multi-channel parallel LED lamp groups, and improve the efficiency of the circuit

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