Switching power supply is a type of power supply, its working principle is through the switching device (such as MOS tube) to control the power supply input voltage switching, to achieve the output voltage, current regulation and stabilization, so as to provide a stable power supply to the electronic equipment. Switching power supply has the advantages of high efficiency, small size, light weight, high reliability, etc., widely used in a variety of electronic equipment.
Principle of operation
The principle of operation of the switching power supply consists of two main parts: the input side and the output side. The input side is mainly composed of rectifier, filter, power factor correction and other circuits, its role is to convert alternating current into direct current, and the current filtering and correction, so that it meets the requirements of electronic equipment. The output side is mainly composed of switching tubes, transformers, filters, voltage regulators and other circuits, whose role is to convert DC power into a stable output voltage and current for electronic equipment.
On the input side, when the AC power enters the rectifier circuit, it is rectified into DC power, but the waveform of DC power is not smooth and there is a large ripple. Therefore, filtering is needed to filter out the ripples in the DC to get a smooth DC. In addition, in order to improve the power factor of the power supply, it is also necessary to carry out power factor correction, so that the power supply can better adapt to the load changes of electronic equipment.
On the output side, the switching tube is the key device. When the switching tube conducts, the power supply outputs current; when the switching tube cuts off, the power supply does not output current. By controlling the conduction and cutoff of the switching tube, the regulation and stabilization of the output voltage and current can be realized. The role of the transformer is to carry out voltage conversion, high-voltage DC converted to low-voltage DC, and isolation. The function of the filter circuit is to filter out the ripple in the output current and get a smooth output current. The function of the voltage regulator circuit is to stabilize the output voltage to ensure the accuracy and stability of the output voltage.
Application Scenarios
Switching power supplies are widely used in a variety of electronic equipment, such as computers, communication equipment, industrial automation equipment, medical equipment, LED lighting and so on. Among them, LED lighting is an important field of switching power supply application. As LED lamp beads have more demanding requirements on voltage and current, they need a stable power supply, so switching power supply becomes the preferred type of power supply for LED lighting.
Operating steps
1. Understand the power supply parameters: When choosing a switching power supply, you need to understand the power supply's output voltage, output current, output power and other parameters to ensure that the power supply can meet the requirements of the electronic equipment.
2. Installation of the power supply: Install the switching power supply in the electronic equipment, connect the input and output terminals, and make sure that the positive and negative poles of the power supply are connected correctly.
3. Adjusting power supply parameters: Adjust the output voltage and current through the adjustment device of the switching power supply to make it meet the requirements of the electronic equipment.
4. Conducting tests: Use test instruments to test the electronic equipment and check whether the output voltage and current of the power supply are stable and meet the requirements.