Basic Composition of High-Power Switching Power Supplies
1. AC power input is rectified and filtered into DC;
2. By using high-frequency PWM (pulse width modulation) signals to control the switching transistor, the DC is applied to the primary of the switching transformer;
3. The secondary induction of the switching transformer generates high-frequency voltage, which is rectified and filtered to supply the load;
4. The output part is fed back to the control circuit through a certain circuit to control the PWM duty cycle, in order to achieve stable output
5. When inputting AC power, it is generally necessary to pass through something like an eddy current loop to filter out interference on the power grid, as well as to filter out interference from the power source on the grid;
6. 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;
7. The secondary of a switching transformer can have multiple windings or one winding can have multiple taps to obtain the desired output;
8. Generally, some protective circuits should be added, such as no-load and short circuit protection, otherwise it may burn out the switch power supply
Basic components of high-power switching power supply
The high-power power supply consists of four main parts: the main power circuit, PWM control circuit, microcontroller control circuit, and auxiliary power supply.
Main power circuit
Impulse current limiting: Limit 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 that exists in the power grid and hinder the feedback of the clutter generated by the machine back to the power grid.
Rectification and filtering: Directly rectify the AC power supply of the power grid into smoother DC power.
Inverter: Convert rectified DC power into high-frequency AC power, which is the core part of high-frequency switching power supply.
Output rectification and filtering: Provide stable and reliable DC power supply according to load requirements.
