Introduction to Switching Power Supply
Switch Mode Power Supply (SMPS), also known as switching power supply or switching converter, is a high-frequency power conversion device and a type of power supply. Its function is to convert a voltage of a certain level into the voltage or current required by the user through different forms of architecture. The input of the switching power supply is mostly AC power (such as mains) or DC power, and the output is mostly equipment that requires DC power, such as personal computers, and the switching power supply performs voltage and current conversion between the two.
Switching power supply is different from linear power supply. The switching transistors used in the switching power supply mostly switch between the full-on mode (saturation zone) and the full-off mode (cut-off zone).
Both modes have the characteristics of low dissipation. The conversion between switching will have higher dissipation, but the time is very short, so it is more energy-saving and generates less waste heat. Ideally, the switching power supply itself does not consume electrical energy. Voltage regulation is achieved by adjusting the time when the transistor is turned on and off.
On the contrary, in the process of generating output voltage, the transistor of the linear power supply works in the amplification zone, which also consumes electrical energy.
The high conversion efficiency of the switching power supply is one of its major advantages. Moreover, because the switching power supply has a high operating frequency, a small-sized and light-weight transformer can be used. Therefore, the switching power supply will be smaller in size and lighter in weight than the linear power supply.
If the high efficiency, volume and weight of the power supply are the key considerations, the switching power supply is better than the linear power supply.
However, the switching power supply is more complicated, and the internal transistors will switch frequently. If the switching current has not been processed, noise and electromagnetic interference may be generated to affect other devices. Moreover, if the switching power supply is not specially designed, its power factor may not be high.
Main uses
Switching power supply products are widely used in industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communication equipment, power equipment, instrumentation, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators, LCD monitors, LED lamps, communication equipment, audio-visual products, security monitoring, LED light strips, computer cases, digital products and instruments.
