Working principle of DC switching power supply Classification of DC switching power supply
DC switching power supply uses a circuit to control the switching tube to conduct high-speed on and off. The alternating current is supplied to the transformer for conversion into high-frequency direct current, thereby generating the required set or sets of voltages! The reason why it is converted into high-frequency alternating current is that the efficiency of high-frequency alternating current in the transformer circuit is much higher than that of 50HZ. Therefore, the switching transformer can be made very small, and it is not very hot when working! ! The cost is very low. If 50HZ is not changed to high frequency, then the switching power supply is meaningless.
working principle
1. The AC power input is rectified and filtered into DC;
2. Control the switching tube through a high-frequency pWM (pulse width modulation) signal, and add that DC to the primary of the switching transformer;
3. The high-frequency voltage is induced in the secondary of the switching transformer and supplied to the load through rectification and filtering;
4. The output part feeds back to the control circuit through a certain circuit to control the pWM duty cycle to achieve stable output.
When AC power is input, it generally has to pass through something like an electrical current loop to filter out interference on the power grid and at the same time filter out interference from the power supply to the grid;
When the power is the same, the higher the switching frequency, the smaller the size 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 with multiple taps to obtain the required output;
Generally, some protection circuits should be added, such as no-load, short-circuit and other protections, otherwise the switching power supply may be burned.
Mainly used in industry and some household appliances, such as televisions, computers, etc.
Classification of DC switching power supplies
High frequency switching DC power supply
The high-frequency switching DC power supply [1] uses high-quality imported IGBT as the main power device and ultra-microcrystalline (also known as nanocrystalline) soft magnetic alloy material as the main transformer core. The main control system adopts multi-loop control technology. Measures have been taken to prevent salt spray and acidification. The power supply product has a reasonable structure and strong reliability. This power supply has become an updated product of silicon controlled power supply with its superior performance of small size, light weight, high efficiency and high reliability. It is suitable for various precision surface treatment places such as experiments, oxidation, electrolysis, galvanizing, nickel plating, tin plating, chromium plating, photoelectricity, smelting, chemical formation, corrosion, etc. It has also received unanimous praise from users in aspects such as anodizing, vacuum coating, electrolysis, electrophoresis, water treatment, aging of electronic products, electric heating, and electrochemistry. Especially in the fields of PCB, electroplating and electrolysis industries, it has become the first choice power supply product for many customers.
