As a highly efficient power conversion device, the switched mode power supply (SMPS) is widely used in various fields, such as home appliances, industrial equipment, communication equipment, and office equipment. So, what is a typical example of a switch mode power supply? In this article, we will explore some typical examples of SMPS in practical applications through several question-and-answer discussions, explain how it works and why it is so popular.

What is the basic working principle of a switch mode power supply?

Before understanding the practical application of SMPS, we need to understand how it works. The core function of SMPS is to efficiently convert electrical energy from one form to another, usually from alternating current (AC) to direct current (DC), but other forms of conversion can also be performed, such as direct current to direct current (DC-DC) conversion or alternating current to alternating current (AC-AC) conversion.

The main working steps of SMPS are as follows:

Rectification and filtering: First, the input AC power is converted to unfiltered DC by a rectifier. This step converts the waveform into DC, but the voltage may not be smooth enough, so a filter is needed to further smooth the voltage.

High-frequency switching: Next, the switch mode power supply converts the DC power into high-frequency pulse current through high-frequency switching. This is one of the most significant differences from traditional linear power supplies. Since high-frequency switches can switch on and off quickly, the efficiency of power conversion is significantly improved.

Transformer regulates voltage: These high-frequency pulse currents pass through a small transformer, which can regulate the output voltage. High-frequency operation greatly reduces the size of the transformer, which is why SMPS is lighter than traditional power supplies.

Rectification and output: Finally, the high-frequency pulse current is converted back to DC through the output rectifier, and a stable DC voltage is output through the filter.

This workflow not only improves conversion efficiency, but also reduces energy loss, making SMPS extremely common in modern electronic devices.

What are the applications of switching power supplies in computers?

Computer power supplies are one of the most common applications of SMPS, especially in desktop computers and servers. The power module inside most computers is an SMPS, which is responsible for converting AC power into multiple DC power of different voltages to power various components in the computer.

ATX power supply: ATX power supply is the standard power supply format in computers, a typical SMPS design. It converts 220V or 110V AC into 3.3V, 5V, and 12V DC, which are used to power the motherboard, hard disk, optical drive, graphics card, etc. The switch mode power supply technology in the ATX power supply can quickly adjust the output voltage to ensure that the computer can run stably under high or low load conditions.

High efficiency and small size: SMPS is more efficient than traditional linear power supplies, and can convert more electrical energy into useful power, reducing the waste of electrical energy. This also greatly reduces the size of the computer power supply, which can free up more space inside the computer for the layout of other hardware.

Overload protection and stability: SMPS has complete overload, overvoltage, and short-circuit protection functions, and can automatically shut down the power supply when the voltage or current is abnormal to prevent hardware damage. This is one of the reasons why switching power supply is widely used in modern computers.

The SMPS in the computer not only provides a stable power supply, but also greatly improves the energy efficiency of the system, allowing the computer to maintain efficient operation in a complex working environment.

What are examples of switching power supplies in household appliances?

SMPS is also widely used in modern household appliances, especially in devices that need to convert high-voltage AC power to low-voltage DC power. Here are some typical examples of household appliances:

TV: Modern LCD and LED TVs have built-in SMPS, which is responsible for converting the 220V AC power of the home grid into the low-voltage DC power required by the TV. The SMPS can power the display panel, sound system and motherboard of the TV. Its efficient energy conversion characteristics not only reduce energy waste, but also make the TV more energy-efficient.

Mobile phone charger: Mobile phone charger is another common SMPS application. Small USB chargers usually use a switch mode power supply inside to convert AC power to 5V, 9V or 12V DC power for charging electronic devices such as mobile phones. Compared with the old transformer charger, SMPS chargers are not only small in size, but also have high charging efficiency and low heat generation.

Microwave oven: The SMPS in the microwave oven is used to provide a stable current for the microwave generator. Since microwave ovens require higher power support, the SMPS can quickly adjust the voltage and current to ensure that the microwave oven can work stably in different cooking modes. The application of SMPS technology also makes the microwave oven smaller in size and reduces power consumption.

Audio system: SMPS is also widely used in home audio and home theater systems. Audio systems require multiple different voltages to power speakers, amplifiers, and processors, and the multi-voltage output characteristics of SMPS make it an ideal choice. SMPS can dynamically adjust the power output according to the needs of the audio, ensuring the stability of sound quality and the safety of the equipment.

SMPS in home appliances not only improves the efficiency of the equipment, but also makes these equipment more energy-efficient and lightweight.

What are the applications of SMPS in industrial equipment?

In industrial environments, the high efficiency, stability, and adaptability of SMPS make it a core component of many devices. The following are some typical applications of SMPS in industrial equipment:

CNC machine tools: CNC machine tools (CNC) usually require multiple voltages to drive different components, such as stepper motors, servo motors, and control circuit boards. SMPS can provide stable voltage and current for these devices, allowing the machine tools to complete various processing tasks with high precision. In addition, the overload protection function of SMPS can automatically cut off the power supply when the current is too high to protect the equipment from damage.

3D printers: 3D printers are becoming more and more popular in industrial and personal use, and SMPS plays a vital role in these devices. 3D printers require multiple voltages to heat the print head, drive the motor, and control the electronic components, and the multi-voltage output capability of the SMPS can meet these needs. It also ensures that the printer maintains a stable power supply during long-term operation, improving the printing quality.

Robotics: Modern industrial robots are used in factories for automated production, and SMPS provides power for various motors, sensors, and control systems of the robots. Since robots need to work in various complex environments, the efficiency and stability of the SMPS are very important to ensure that the robots will not fail due to power problems during operation.

Communication equipment: Many industrial communication devices, such as servers, routers, and switches, rely on SMPS to provide stable power. These devices usually need to operate 24 hours a day, so the power supply requirements are very high. SMPS not only provides stable voltage, but also can maintain the stability of the output voltage when the power grid fluctuates, avoiding equipment failure due to voltage fluctuations.

SMPS in industrial equipment must have high reliability, long life, and low energy consumption to ensure continuous and efficient operation even in harsh working environments.

Conclusion

Switch mode power supplies (SMPS) are widely used in all aspects of modern society. From computer power supplies, home appliances to industrial equipment, switching mode power supply has become the only choice for power conversion equipment with its high efficiency, lightness and stability. Whether it is to provide convenience for daily life or to improve efficiency in industrial production, SMPS has demonstrated its irreplaceable role.

Understanding the working principle of SMPS and its application in different fields can help us better understand the power supply system behind these electrical equipment. At the same time, with the advancement of technology, the performance and application scope of SMPS will be further expanded, providing more efficient and reliable power solutions for more fields.