Multiplexed output high-precision constant-voltage power supply and control method thereof

Abstract

The invention provides a multiplexed output high-precision constant-voltage power supply, which comprises: a power supply module, a transformer, a plurality of secondary rectifying circuits and a constant-voltage control circuit, the number of the constant-voltage control circuit is one less than that of the secondary rectifying circuits, and the power supply module is connected with the input endof the transformer, the output end of the transformer is connected with the input ends of the secondary rectifying circuits in parallel, the output of the first secondary rectifying circuit serves asmain power output, and the feedback signal output end of the first secondary rectifying circuit is connected with the feedback signal input end of the power supply module; and the output ends of theother secondary rectifying circuits are connected with the constant-voltage control circuit and then output as corresponding secondary power supplies. The multiplexed output rectifying circuits are combined in parallel, secondary energy conversion is not needed, the system efficiency is high, and the loss is small; and each path of output can be independently subjected to voltage control, the application range is wide, and a low-cost and high-precision voltage control mode is realized.

Description

technical field [0001] This patent relates to the field of display power supplies with two or more outputs, and is a switching power supply control circuit with high conversion efficiency and high constant voltage precision. Background technique [0002] In the field of display power supply, two-way output or multi-way output refers to the direct output of two-way power supply or multi-way power supply from one transformer. Due to the cross-effect of the load size of each way, the change of load will cause the output voltage of the second group to be relatively different. Large changes, even beyond the power specification requirements. [0003] If you want to stabilize the voltage of each group of power supplies with high precision, taking two outputs as an example, the following methods can be used at present: 1. Two independent constant voltage power supplies. 2. One way is the main constant voltage power supply, and the second way is obtained from the main power supply s...

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Problems solved by technology

[0004] The first way, the advantage is that the two outputs can be accurate and constant voltage, and the conversion efficiency is high; the disadvantage is that the cost is high

[0005] The second method has the advantage that the two outputs can be accurately constant voltage; the disadvantage is that due to the existence of secondary constant voltage, for low-voltage and high-current power supplies, it is difficult to select power supply materials, high cost, and low system conversion efficiency

The disadvantage is that the power loss is large and the system conversion efficiency is low

[0007] The fourth method has the advantage of high power supply efficiency; the disadvantage is that the output voltage of the second channel varies greatly and cannot be accurately constant voltage

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