Differences between Switching Power Supplies and Linear Power Supplies and Their Respective Application Areas

When we are purchasing power supplies, we often encounter two kinds of power supplies with similar appearance: switch power supply and linear power supply.

Here is a brief explanation of switching power supplies and linear power supplies:

Switching Power Supply

A switching power supply is a type of power supply that converts input AC or DC power into high - frequency pulse signals by controlling the on - and - off states of switching transistors. Then, through processes like voltage transformation by a transformer, rectification, and filtering, it finally outputs stable DC voltage. It features high efficiency, small size, and light weight, but may have some voltage ripple and electromagnetic interference.

Linear Power Supply

A linear power supply first converts input AC power into DC power, and then stabilizes the output voltage through a regulating transistor. The regulating transistor works in the linear amplification region, controlling the output voltage by changing its own resistance. It has the advantages of high - stability output voltage, low ripple coefficient, and little electromagnetic interference, but its efficiency is relatively low, and it usually requires a large heat - dissipation device, resulting in a large size and weight.

Linear power supplies and switching power supplies each have their own advantages and disadvantages, and are suitable for different application scenarios.

Advantages and Disadvantages of Switching Power Supplies

Advantages

1. High Efficiency: The switching transistors of switching power supplies operate in the on - off state, with low power consumption. The overall efficiency can usually reach over 80%, and some even exceed 90%.

2. Small Volume and Light Weight: Switching power supplies use high - frequency transformers and smaller components, greatly reducing the overall volume and weight, which is suitable for miniaturized designs.

3. Wide Input Range: Switching power supplies can adapt to a wide input voltage range, generally between 160V - 270V, and can meet the power grid voltage standards of different countries and regions.

4. Fast Dynamic Response: Switching power supplies can quickly adjust the output voltage to cope with load changes, making them suitable for applications with frequent switching or large load variations.

Disadvantages

1. High Electromagnetic Interference: When switching power supplies are working, they generate rapidly changing currents and voltages, which are prone to produce electromagnetic interference (EMI), potentially affecting surrounding electronic devices.

2. Large Output Ripple: The output ripple of switching power supplies is relatively large, which may affect the quality of audio and video.

3. Complex Design and Difficult Maintenance: The design of switching power supplies is complex, and professional personnel are required for repair, resulting in high costs.

Advantages and Disadvantages of Linear Power Supplies

Advantages

1. Low Efficiency but High Stability: The regulating transistor of a linear power supply always operates in the linear amplification region, which does not introduce additional interference. It has low electromagnetic interference and a low ripple coefficient, making it suitable for applications with high requirements for power stability.

2. Simple Design and Easy Maintenance: Linear power supplies have a relatively simple structure and low maintenance costs. Technicians with basic knowledge of electronics can repair them.

3. Good Lightning Protection Performance: Due to the structure of the transformer, linear power supplies can strongly suppress instantaneous high voltages and have strong lightning protection capabilities.

Disadvantages

1. Low Efficiency: The regulating transistor of a linear power supply always operates in the linear amplification region, resulting in iron and copper losses. The efficiency is generally around 50%.

2. Large Volume and Heavy Weight: Linear power supplies require a power frequency transformer and large filter capacitors, leading to a large volume and heavy weight.

3. Narrow Input Range: The input voltage range of linear power supplies is relatively narrow, generally between 200V - 240V or 90V-130V and is not suitable for environments with large voltage fluctuations. (While Switching Power Supply's input voltage can range from 90V-260V.)

Different Application Areas

Application Scenarios of Switching Power Supplies

Consumer Electronics Field

1. Mobile Devices such as Mobile Phones and Tablets;

2. Laptop Computers;

3. Home Entertainment Devices such as TVs and Set - Top Boxes.

Industrial Automation Field

1. Devices such as Programmable Logic Controllers (PLCs) and Industrial Robots;

2. Factory Automation Production Lines.

Communication Field

1. Communication Equipment such as Base Stations and Servers;

2. Data Centers.

   
   

Application Scenarios of Linear Power Supplies

Precision Instrument and Meter Field

1. Laboratory Instruments;

2. Medical Equipment.

Audio Amplifier Field

1. High - Fidelity Audio Equipment;

2. Professional Recording Equipment.

Special Application Fields

1. Aerospace Field;

2. Military Field.

Briefly Summarized

1. Reasons for the Generation of Ripple and Noise

2. Measures to Reduce Ripple and Noise Voltage

In Detail