Working principle of DC power supply-Classification of DC power supply
working principle
1. AC power input is rectified and filtered into DC;
2. Control the switching tube through the high-frequency pWM (pulse width modulation) signal, and add the DC to the primary of the switching transformer;
3. The secondary side of the switching transformer induces a high-frequency voltage, which is rectified and filtered to supply the load;
4. The output part feeds 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 generally passes through something like a current circle to filter out the interference on the power grid, and at the same time filter out the interference from the power supply to the power 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 a 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 TV sets, computers, etc.
Classification of DC switching power supply
High Frequency Switching DC Power Supply
High-frequency switching DC power supply [1] uses high-quality imported IGBT as the main power device, and uses ultra-microcrystalline (also known as nanocrystalline) soft magnetic alloy material as the main transformer core. The main control system adopts multi-loop control technology. Anti-salt spray acidification measures have been taken. The power supply product has a reasonable structure and strong reliability. The power supply has become an updated product of the thyristor power supply due to its small size, light weight, high efficiency, and high reliability. It is suitable for various precision surface treatment places such as experiment, oxidation, electrolysis, galvanizing, nickel plating, tin plating, chrome plating, photoelectricity, smelting, chemical formation, corrosion, etc. In anodizing, vacuum coating, electrolysis, electrophoresis, water treatment, electronic product aging, electric heating, electrochemistry, etc., it has also received unanimous praise from users. Especially in the pCB, electroplating, and electrolysis industries, it has become the preferred power supply product for many customers.
Application Features
1. Reduce the porosity, the formation speed of crystal nuclei is faster than the growth speed, which promotes the refinement of crystal nuclei.
2. Improve the binding force, make the passivation film break down, and help the firm combination between the substrate and the coating.
3. Improve the covering ability and dispersing ability, the high cathode negative potential can also deposit the passivated parts in ordinary electroplating, and slow down the "burning" and "dendritic" of the protruding parts of complex parts due to excessive consumption of deposited ions For deposition defects, the thickness of a coating with a given characteristic (such as color, no porosity, etc.) can be reduced to 1/3~1/2 of the original, saving raw materials.
4. Reduce the internal stress of the coating, improve lattice defects, impurities, voids, tumors, etc., easily obtain a crack-free coating, and reduce additives.
5. It is beneficial to obtain alloy coating with stable composition.
6. To improve the dissolution of the anode, no anode activator is required.
7. Improve the mechanical and physical properties of the coating, such as increasing the density to reduce the surface resistance and volume resistance, improving toughness, wear resistance, corrosion resistance and controlling the hardness of the coating.
Composition of DC switching power supply
The whole process of direct and main circuit input from AC grid and DC output: [
1. Input filter: Its function is to filter the clutter existing in the power grid, and at the same time prevent the clutter generated by the machine from feeding back to the public power grid.
2. Rectification and filtering: directly rectify the AC power of the grid into a smoother DC for the next stage of transformation.
3. Inversion: Convert the rectified direct current into high-frequency alternating current, which is the core part of the high-frequency switching power supply. The higher the frequency, the smaller the ratio of volume, weight and output power.
4. Output rectification and filtering: According to load requirements, provide stable and reliable DC power supply.
