Multichannel multiphase-driving LED (Light Emitting Diode) power supply

Abstract

The invention relates to a multichannel multiphase-driving LED (Light Emitting Diode) power supply and a phase control method, particularly relating to a multiphase power supply method of multiphase constant current or constant voltage and constant current by adopting single-string or multiple-string LEDs for lighting. Aiming at overcoming the shortage and defect in the prior art, the invention provides the multichannel multiphase-driving LED power supply which can distribute total output current to each channel. Since the channels have same switching frequency and different phases, as well as relatively independent constant current or constant voltage control, the current differences of each string of LED subcircuits caused by the inconformity of each string of LED parameters when multiple strings of LEDs are directly connected in parallel can be eliminated. The invention also provides a multichannel multiphase-driving single-string LED driving solution.

Description

technical field [0001] The invention relates to a multi-channel multi-phase driven LED power supply method, in particular to a multi-phase constant current or constant voltage-constant current multi-phase power supply method for lighting with single or multiple strings of LEDs. Background technique [0002] Nowadays, most LED lighting at home and abroad adopts the series connection method of LED chip particles. The current through each LED is the same in the series connection method, which is easy to be driven by constant current. However, when the lighting power increases and more LED particles are connected in series, the terminal voltage increases accordingly. Causes the contradiction between high power and safety regulations; in order to achieve low voltage and high power, the series-parallel hybrid connection method of multiple strings of LEDs in parallel is the most used connection method for high-power LED lamps. The advantage of this connection method is that the driv...

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Problems solved by technology

[0002] Nowadays, most LED lighting at home and abroad adopts the series connection method of LED chip particles. The current through each LED is the same in the series connection method, which is easy to be driven by constant current. However, when the lighting power increases and more LED particles are connected in series, the terminal voltage increases accordingly. Causes the contradiction between high power and safety regulations; in order to achieve low voltage and high power, the series-parallel hybrid connection method of multiple strings of LEDs in parallel is the most used connection method for high-power LED lamps. The advantage of this connection method is that the driving circuit is simple and the cost is low. Low, but because the LED conduction voltage drop changes with temperature, current and other environmental factors, it is difficult to ensure that the parameters of each string of LEDs are completely consistent. This difference leads to different currents distributed in different LED series branches, resulting in different branches. The brightness of the LEDs is uneven, the heat generation is uneven, and the light decay and life of each branch LED are inconsistent. In severe cases, the entire high-power LED and power supply will fail.

[0003] The above-mentioned LED lighting driving power supply is usually a single-channel switch driving structure. No matter how many LEDs are connected in parallel, there is usually only one power drive channel. The peak current and ripple current of this single-channel switch drive are large, and the filter capacitor is large. The current loss of the power supply is large, which will affect the life of the power supply and improve the efficiency, and it is easy to generate large electromagnetic interference

[0004] In addition, the existing LED power supply adopts a multi-channel switch drive structure, and the switch drive circuits of each channel are simply pieced together. The disadvantage is that each channel is not related to each other, independent of each other, and has large electromagnetic interference, and even causes problems such as beat flicker interference.

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