Circuit for regulating and controlling output power of power supply

Abstract

The invention provides a circuit for regulating and controlling an output power of a power supply, which comprises signal generating circuit, a photoelectric coupling circuit, a transformation switching circuit and a thyristor. The thyristor is connected between the power supply and a load. The signal generating circuit generates a first pulse signal having an adjustable duty ratio and provides the first pulse signal to the photoelectric coupling circuit. When the first pulse signal has a high electric level, the photoelectric coupling circuit is closed and the photoelectric coupling circuit outputs a sinusoidal signal. The sinusoidal signal is converted into a second pulse signal through the transformation switching circuit so as to control the on and off of the thyristor. When the second pulse signal has a high electric level, the thyristor is turned on and the power supply supplies a power to the load; and when second pulse signal has a low electric level, the thyristor is turned off and the power supply does not supply the power to the load. The circuit for regulating and controlling the output power of the power supply uses the photoelectric coupling circuit to isolate the signal generating circuit and the transformation switching circuit. The photoelectric coupling circuit can effectively inhibit common code interference, and the signal generating circuit regulates and controls the output power of the power supply in unit time by regulating the duty ratio of the first pulse signal.

Description

technical field [0001] The invention relates to a power supply output power regulating circuit. Background technique [0002] Power supply is a widely used power supply device, and its output power control technology is very important for the stability of electronic equipment in various environments. Generally speaking, the driving stage of the power output power regulating circuit uses a self-excited circuit to generate a control signal, and then regulates the output power of the power supply. However, the working performance of the self-excited circuit is greatly affected by environmental changes, especially its ability to resist common-mode interference is poor, which makes the stability of the control signal for regulating the output power of the power supply not high. How to provide a circuit capable of stably regulating the output power of the power supply has become an urgent problem to be solved. Contents of the invention [0003] In view of the above, it is nece...

AI Technical Summary

Problems solved by technology

However, the working performance of the self-excited circuit is greatly affected by environmental changes, especially its poor anti-common-mode interference ability, which makes the stability of the control signal for regulating the output power of the power supply not high

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