Efficient power source capable of supplying electricity in constant voltage and constant current alternation mode

Abstract

The invention discloses an efficient power source capable of supplying electricity in a constant voltage and constant current alternation mode. The efficient power source capable of supplying the electricity in the constant voltage and constant current alternation mode comprises a power source, an EMI filter, a rectifier and filter module, a power factor correction module, a power management IC module and an LLC transformer module, which are connected in sequence, wherein the LLC transformer module outputs two types of windings which are respectively used as windings of a high voltage and constant current output module and a low voltage and constant voltage output module. The efficient power source capable of supplying the electricity in the constant voltage and constant current alternation mode effectively uses an efficient control mode of PWM (pulse width modulation) of an LED (light emitting diode) backlight, outputs a constant voltage source and a constant current source which alternately work under loop control by only using a transformer, not only can meet the constant current requirement of the LED backlight, but also can meet the constant voltage source requirement of a machine core, simplifies an electric circuit due to the fact that no constant current board or no accessory power source needs to be manufactured, achieves low power consumption in a standby mode, and reduces system cost, and furthermore efficiency of the power source is improved.

Description

technical field [0001] The invention relates to a power supply, in particular to a high-efficiency power supply with constant voltage and constant current alternating power supply. Background technique [0002] With the development of technology, the popularization of energy-saving policies for the benefit of the people, the improvement of electrical energy efficiency index standards has attracted more and more attention from enterprises. At present, when large-size LED TVs are working, the power consumption of the screen accounts for more than 70% of the power consumption of the whole machine, and the current power supply structure of the TV is that after the AC power is input to the TV, it is corrected by the PFC power factor and then passed through the AC-DC power supply. Conversion, and then after DC-DC power conversion and boosting, power is supplied to the backlight strip, so that the energy efficiency of the backlight strip reaches 80%. However, in the above-mentione...

AI Technical Summary

Problems solved by technology

However, in the above-mentioned TV power supply architecture, after the AC power passes through the PFC, it needs to go through two stages of conversion: AC-DC constant voltage power conversion and DC-DC boost constant current conversion to supply power to the backlight strip. The energy efficiency of the backlight power supply part is low, and one more conversion also makes the cost higher

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