Switching power supply is composed of four major parts: main circuit, control circuit, detection circuit, and auxiliary power supply.
1. Main circuit
Impulse current limiting: limits the impulse current on the input side at the moment the power is turned on.
Input filter: Its function is to filter out the clutter existing in the power grid and feedback the clutter that hinders the generation of the machine back to the power grid.
Rectification and filtering: Directly rectifying the AC power supply of the power grid into smoother DC power.
Inversion: Transforming rectified DC power into high-frequency AC power, which is the core part of high-frequency switching power supplies.
Output rectification and filtering: Provide stable and reliable DC power supply according to load requirements.
2. Control circuit
On the one hand, samples are taken from the output end, compared with the set value, and then the inverter is controlled to change its pulse width or frequency to ensure stable output. On the other hand, based on the data provided by the test circuit and identified by the protection circuit, control circuits are provided to provide various protection measures for the power supply.
3. Detection circuit
Provide various parameters and instrument data that are currently in operation in the protection circuit.
4. Auxiliary power supply
Implement software (remote) startup of the power supply to provide power for the protection circuit and control circuit (PWM and other chips).