Hybrid multi-output power supply and regulating method thereof

Abstract

The invention provides a composite multi-output power supply and its adjustment method, which are used to generate a constant voltage output to drive a load, and to generate a constant current output to drive an LED, including a first-stage voltage regulation circuit, a second-stage The voltage regulation circuit and the driving circuit only need a first-stage voltage conversion circuit to obtain the driving voltage required to support the subsequent LED, and the implementation circuit and control scheme are relatively simple, which simplifies the circuit structure and reduces the implementation cost; moreover, it can The first regulation voltage is adjusted according to the change of the LED current, so that its value can follow the change of the LED current, and always keep the minimum voltage value that can drive all the circuits of the LED, thereby improving the power conversion efficiency to the greatest extent.

Description

technical field [0001] The present invention relates to the field of electronic technology, and more specifically, relates to a power supply with multiple outputs and an adjusting method thereof applied to an LED device, a driving circuit and a driving method thereof. Background technique [0002] With the continuous innovation of liquid crystal display technology and the increase of application products, LED backlight has developed rapidly due to the advantages of energy saving, environmental protection and light and thin volume. However, since the brightness of an LED lamp is related to the light output intensity parameter, it is directly proportional to its current and forward voltage drop, and changes with temperature. Therefore, the driving of LED requires a constant current power supply to ensure the safety of LED use and achieve ideal luminous intensity at the same time. It can be seen that it is very important to choose the correct LED driver. Without a good LED dr...

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Problems solved by technology

[0009] Moreover, the output power of the driving circuit part for realizing the constant current output of the LED is generally greater than the output power of the driving circuit part for realizing the constant voltage output, so the conversion efficiency of the LED driving power supply is relatively low

At the same time, the feedback of the driving circuit part that realizes the constant voltage output is usually transmitted to the controller 102 using optocouplers (IC1A and IC1B), so the transient response is relatively slow

In order to achieve a better adjustment accuracy of the output voltage, more output capacitors are required, which also leads to an increase in cost

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