With the wide application of switching power supply in computer, communication, aerospace, instrumentation and household appliances, the demand for switching power supply is increasing, and higher requirements are put forward for the efficiency, volume, weight and reliability of power supply. Switching power supply with its high efficiency, small size, light weight and other advantages has gradually replaced the low efficiency and bulky linear power supply in many aspects. With the development of power electronics technology, especially the rapid development of high-power devices IGBT and MOSFET, the working frequency of switching power supply has been raised to a very high level, which makes it have the characteristics of high stability and high cost performance.

Introduction to switching power supply

Switching mode power supply, also known as switching mode power supply and switching converter, is a high-frequency power conversion device. Its function is to convert a bit level voltage into the voltage or current required by the client through different architectures.


2. Design of CNC buck switching power supply based on 51 single chip microcomputer

Function introduction:

Hardware system composition: STC12C5A60S2 MCU + IR2104 driver + buck circuit + 1602 LCD + button;

LCD display: input voltage, preset output voltage, output current, working state (over current, input under voltage, input over voltage)

Default output mode: constant voltage output;

Output voltage range: 0-input voltage * 90%. If the actual input voltage is 40V, the maximum output voltage is 36V

Working mode: Buck buck buck;

Rectification mode: non synchronous rectification;

Switching frequency: 43khz;

The maximum conversion efficiency was 89%;

Maximum output current: 1.0A;

Over current protection: the over-current protection value is 1.2A, which is cut off in case of over-current;

Ripple range: ≤ 200mV;


3. Circuit scheme of high power switching power supply

Mature scheme. The instantaneous power can reach above 150W. Working in low power range for a long time. About 80W.

Suitable for short time, high power. And the general working power is relatively small.

Output two 15v1a, one 60V.

It can input 220 v. If the input voltage is 110V, the starting resistance can be changed. And the same resistance will do.

The scheme is verified, but the filter and power supply are separated.


4. Circuit design of DC-DC switching power supply based on 51 single chip microcomputer

This document is based on 51 single-chip microcomputer DC-DC switching power supply circuit design, a complete design circuit schematic diagram, can directly imitate the drawing board, there are needs of small partners can directly download.


5. Circuit scheme of isolated low cost switching power supply

Lp2702a is a high efficiency and high precision driver chip for constant voltage control of non isolated step-down switching power supply. The non isolated buck topology is suitable for 85vac ~ 265vac full range input voltage, especially for small household appliances, white household appliances and other power supply drivers. Lp2702a is integrated with 500V power switch and adopts a unique constant voltage control mode. The system can work in the intermittent mode and continuous mode of inductive current. The scheme is flexible in design, simple in peripheral application, and can achieve higher output power with lower system cost.

Jw3510 is a micro power isolated flyback converter, which outputs the voltage waveform directly from the primary flyback by sampling and isolation, and does not need a third winding or an optical isolator for regulation. The output voltage can be programmed with an external resistor. In addition, internal compensation and soft start further reduce the external component count. The jw3510 operates from 3.0V to 42V in the input voltage range and outputs 5V stably.

The switching power supply is based on lp2702a low-cost non isolated step-down AC 220 V, and the unstable voltage of about 12 V is obtained by filtering. The module is safe and reliable, with short-circuit protection, over-current protection function. When the load is too large, the power supply will appear intermittent on-off abnormal conditions. It also has the characteristics of low cost and small volume.

Title: pay homage to the classic, 10 switching power supply solutions tell you what is the evergreen tree of electronic industry

The source of the article: WeChat official account: circuit design skills] welcome to add attention! Please indicate the source of the article.

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