Switching power supply is to use a circuit to control the switching tube to conduct high-speed on and off.
Convert direct current into high-frequency alternating current and supply it to the transformer for transformation, thereby generating the required one or more sets of voltages! The reason for the conversion to high frequency alternating current is that the efficiency of high frequency alternating current in the transformer transformer circuit is much higher than 50HZ. So the switching transformer can be made very small, and it is not very hot during work! ! The cost is very low. If you don't change 50HZ to high frequency, then the Switching power supply is meaningless.
The workflow of Switching power supply is:
power supply → input filter → full bridge rectification → DC filtering → switching tube (oscillating inverter) → switching transformer → output rectification and filtering.
The AC power input is rectified and filtered into DC
The switching tube is controlled by a high-frequency PWM (pulse width modulation) signal, and that DC is added to the primary of the switching transformer
The secondary of the switching transformer induces high-frequency voltage, which is rectified and filtered to the load
The output part is fed back to the control circuit through a certain circuit to control the PWM duty cycle to achieve the purpose of stable output
When the AC power is input, it usually passes through things such as the current circle to filter out the interference on the power grid, and also filter the interference of the power supply to the power grid;
When the power is the same, the higher the switching frequency, the smaller the volume of the switching transformer, but the higher the requirements for the switching tube;
The secondary of the switching transformer can have multiple windings or one winding has multiple taps to get the required output;
Generally, some protection circuits should be added, such as no-load, short-circuit protection, etc., otherwise the Switching power supply may be burned.
is mainly used in industry and some household appliances, such as televisions, computers, etc.