What are the components of switching power supply
The switching power supply is roughly composed of four parts: the main circuit, the control circuit, the detection circuit and the auxiliary power supply.
1. Main circuit
Inrush current limiter: limit the inrush current on the input side at the moment of power on.
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Input filter: Its function is to filter the clutter existing in the grid and prevent the clutter generated by the machine from feeding back to the grid.
Rectification and filtering: Directly rectify the AC power of the grid into a smoother DC.
Inverter: Transform the rectified DC into high-frequency AC, which is the core part of the high-frequency switching power supply.
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 terminal, compared with the set value, and then the inverter is controlled to change its pulse width or pulse frequency to stabilize the output; on the other hand, according to the data provided by the test circuit, it is identified by the protection circuit and provided The control circuit performs various protection measures on the power supply.
3. Detection circuit
Provide various parameters and various instrument data in operation in the protection circuit.
4. Auxiliary power supply
Realize the software (remote) start of the power supply, and supply power for the protection circuit and control circuit (PWM and other chips).
At present, engineers in the field of switching power supply technology are developing related power electronic devices and switching frequency conversion technology at the same time. The mutual promotion of the two promotes the switching power supply to be light, small, thin, low noise and high reliability with a growth rate of more than two digits every year. , Anti-jamming direction. Switching power supplies can be divided into two categories: AC/DC and DC/DC.
Switching power supply is becoming popular and miniaturized. Switching power supply will gradually replace all applications of transformers in daily life. The application of low-power micro-switching power supply should first be reflected in digital display meters, smart meters, mobile phone chargers, etc. At this stage, the country is vigorously promoting the construction of smart grids, and the requirements for electric energy meters have been greatly increased. Switching power supplies will gradually replace the application of transformers on electric energy meters.
