What is the working principle of switching power supply?

As the world pays more attention to energy issues, the energy consumption of electronic products will become more and more prominent. How to reduce their standby power consumption and improve power supply efficiency has become an urgent problem to be solved. Although the traditional linear stabilized power supply has a simple circuit structure and reliable operation, it has disadvantages such as low efficiency, large volume, large copper and iron consumption, high operating temperature, and small adjustment range. In order to improve efficiency, people have developed a switching power supply with an efficiency of over 85% and a wide range of voltage regulations. In addition, the switching power supply also has the characteristics of high voltage stabilization accuracy and does not use power transformers, making it an ideal regulated power supply. As a kind of switching power supply, the DR-Din rail power supply is also similar to the switching power supply. Now let us introduce the working principle of switching power supply.

Here is the content list:

1.Connection control method

2.Basic circuit

3.Control circuit

Connection control method

Switching power supply connection control methods are divided into two types: width modulation and frequency modulation. In practical applications, width modulation is more commonly used. In the switching power supply integrated circuits currently developed and used, most of them are also pulsed width modulation type. For a unipolar rectangular pulse, the average DC voltage depends on the width of the rectangular pulse. The wider the pulse, the higher the average DC voltage value. The average DC voltage can be calculated by the formula. Under certain conditions, the average DC voltage will be proportional to the pulse width. In this way, as long as we try to make the pulse width narrower as the output voltage of the regulated power supply increases, the purpose of voltage stabilization can be achieved.

Basic circuit

After the AC voltage of the switching power supply is rectified and filtered by the rectifier circuit and the filter circuit, it becomes a DC voltage containing a certain pulsating component, which is converted into a square wave of the required voltage value by the high-frequency converter. Finally, the switching power supply converts the square wave voltage into the required DC voltage through rectification and filtering.

Control circuit

The control circuit of the switching power supply is a pulse width modulator, which is mainly composed of a sampler, a comparator, an oscillator, a pulse width modulation, and a reference voltage circuit. This part of the circuit has now been integrated, and various integrated circuits for switching power supplies have been made. The control circuit is used to adjust the ratio of the switching time of the high-frequency switching element to achieve the purpose of stabilizing the output voltage.

All in all, the working principle of the switching power supply is that the switching power supply is turned on and off at a high speed through the circuit control of the switching tube. The working principle of the DR-Din rail power supply is also similar to that of the switching power supply.

Zhejiang Ximeng Electronic Technology Co., Ltd. is a company specializing in the production of switching power supplies. The company has a group of professionals, you can consider buying our company's products.