The basic composition of a switching power supply is roughly composed of four major parts: the main circuit control circuit, the detection circuit, and the auxiliary power supply.
1. Main circuit
Impact current limiting: Limits the impact current on the input side at the moment of power on.
Input filter: Its function is to filter out the clutter existing in the power grid and feedback back to the power grid the clutter that hinders the generation of the local machine.
Rectification and filtering: Directly rectifying the AC power supply of the power grid into smoother DC power.
Inversion: Transforming the rectified DC power into high-frequency AC power, which is the core part of high-frequency switching power supply.
Outgoing 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 manipulated to change its pulse width or frequency to make the output stable. On the other hand, based on the data provided by the test circuit and identified by the protection circuit, various protection measures are provided for the power supply by the control circuit.
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).