What is the basic working principle of FA1026 power supply?


The working process of a switching power supply is quite easy to understand. In a linear power supply, the power transistor operates in linear mode. Unlike a linear power supply, a PWM switching power supply allows the power transistor to operate in both on and off states, The volt ampere product added to the power transistor is very small (during conduction, the voltage is low and the current is high; during shutdown, the voltage is high and the current is low)/The volt ampere product on the power device is the loss generated on the power semiconductor device.

Compared with linear power sources, the more effective working process of PWM switching power sources is achieved through "chopping", which chops the input DC voltage into a pulse voltage with an amplitude equal to the input voltage amplitude. The duty cycle of the pulse is adjusted by the controller of the switching power supply. Once the input voltage is chopped into an AC square wave, its amplitude can be increased or decreased through a transformer. By increasing the number of secondary windings in the transformer, the number of output voltage groups can be increased. Finally, these AC waveforms are rectified and filtered to obtain a DC output voltage.

The main purpose of the controller is to maintain stable output voltage, and its working process is similar to that of a linear controller. That is to say, the functional block, voltage reference, and error amplifier of the controller can be designed to be the same as the linear regulator. Their difference lies in that the output of the error amplifier (error voltage) needs to pass through a voltage/pulse width conversion unit before driving the power transistor.

There are two main working modes of switching power supply: forward conversion and boost conversion. Although the layout differences between their respective parts are small, the working processes vary greatly and each has its own advantages in specific application scenarios.


What is the workflow of FA1025 power supply?


After the mains power enters the power supply, high-frequency noise and interference signals are first removed through choke coils and capacitor filtering, and then rectified and filtered to obtain high-voltage direct current. Then, the DC power is converted into high-frequency pulsating DC power through a switching circuit, and then the high-frequency switching transformer is sent for voltage reduction. Then filter out the high-frequency AC part, so that the final output is relatively pure low-voltage direct current for computer use.

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