What are the advantages of switching power supply?

(1) Low internal power loss and high conversion efficiency

In some countries where the electronics industry is developed and advanced, the megahertz level can be achieved. This greatly reduces the power loss on the switching power tube V, greatly reduces the inductance of the energy storage inductor, and greatly improves the energy storage power. Therefore, the conversion efficiency of the entire switching power supply can be greatly improved, and its conversion efficiency can be as high as about 90%.

(2) Small size and light weight

It can be clearly seen from the principle circuit diagram of the switching power supply that no bulky power frequency transformer is used here. Since the switching power tube V works in the switching state, its own power loss is greatly reduced, thus eliminating the need for a larger heat sink. In addition, because the operating frequency of the circuit is several orders of magnitude higher than the 50Hz power frequency in the linear stabilized power supply, the filtering efficiency is greatly improved, and the capacity of the filtering capacitor is also greatly reduced. These three reasons make the switching power supply have the obvious characteristics of small size and light weight.

(3) Wide voltage regulation range, high linear adjustment rate

The output voltage of the switching power supply is adjusted by the duty cycle of the pulse width modulation/pulse frequency modulation (PWM/PFM) drive signal. The instability of the output voltage caused by the change of the input signal voltage can be compensated by adjusting the pulse width or the pulse frequency. In this way, when the input power frequency grid voltage changes greatly, the switching power supply can still ensure a very stable output voltage. Therefore, the switching power supply not only has a wide range of voltage regulation, but also has the advantages of good voltage regulation effect and high linear regulation rate. In addition, there are two methods for changing the duty cycle: pulse width modulation and pulse frequency modulation. Therefore, the switching power supply not only has the above-mentioned advantages, but also has many methods and technologies to realize voltage stabilization. The designer can flexibly choose various types of switching power supply circuits according to the requirements and needs of actual applications.

(4) The filter efficiency is greatly improved, and the capacity and volume of the filter capacitor are greatly reduced

The working frequency of the switching power supply is basically above 50Hz, which is more than 1000 times the working frequency of the linear stabilized power supply. Therefore, the filtering efficiency of the switching power supply after rectification is almost increased by about 1000 times. Even if half-wave rectification and capacitor filtering are used, the filtering efficiency of the switching power supply is about 500 times higher than that of the linear regulated power supply.

(5) The circuit forms are flexible and diversified, and the choice is large

For example, there are self-excitation and other excitation, adjustment and frequency modulation, single-ended and double-ended, boost, buck, and polarity reversal. Designers can use their ingenuity and make full use of the advantages of various types of circuits to design switching power supplies that can meet different occasions.