Difference between digital pow supply and switching pow supply
Digital power supply and switching power supply are both kinds of electronic power supply, which are used to convert alternating current into constant direct current for electronic equipment. Although they all belong to the field of power supply, there are many differences between them. This paper will introduce the difference between digital power supply and switching power supply in detail.
1. Principle difference
The working principles of digital power supply and switching power supply are different. Digital power supply (also known as linear power supply) directly stabilizes the output voltage after voltage reduction, rectification and filtering by transformer, and its working principle is similar to the combination of transformer and voltage regulator. The switching power supply adopts switching power supply chip, takes alternating current (AC) as input signal, and finally converts the current into direct current (DC) after rectification, filtering, frequency conversion, voltage transformation and output. Its working principle is similar to the combination of frequency converter and inverter.
2. Stability difference
Because of its direct regulated output, digital power supply has relatively stable output voltage and small ripple. However, the output voltage of switching power supply is difficult to keep stable by high-frequency rectangular wave modulation, which is related to the peak voltage of power supply, load capacity and high-frequency device factors. Therefore, the switching power supply needs to design special feedback and protection circuits, and it needs to be used carefully in applications.
3. Power efficiency difference
Switching power supply usually has good power efficiency, which can reach 85%-ninety-seven percent efficiency, making switching power supply one of the important factors for popularization and use. However, the efficiency of digital power supply is low, generally only between 65% and 80% (only low-power circuits can achieve more than 90% efficiency), which increases its size, weight and cost, and is ignored in modern high-efficiency electronic equipment.
4. The difference between control and protection
Because the control of the voltage stabilizing circuit of digital power supply is relatively simple, there is generally no need for complex defense measures. However, there are some problems in the design, manufacture and use of switching power supply, which may cause power supply noise, excessive temperature, vibration, overvoltage and open circuit. Therefore, it is necessary to solve these problems through control and protection circuits and ensure the stability and reliability of switching power supply.
5. Size and weight difference
Digital power supply is bulky and heavy, and is generally used in electronic equipment with low power. In contrast, switching power supply has the characteristics of high efficiency and small volume, and is suitable for electronic equipment with high power, power density or high power and electricity demand, such as computers, electronic extractors, LED lamps, power tools and so on.
