Switching power supply is different from linear power supply. Most switching transistors used in switching power supply switch between fully open mode (saturation region) and fully closed mode (cutoff region). Both modes have the characteristics of low dissipation, and the switching between switches will have high dissipation, but the time is short, so it saves energy and produces less waste heat. Ideally, the switching power supply itself will not consume power. Voltage stability is achieved by adjusting the turn-on and turn-off time of the transistor. On the contrary, when the linear power supply generates the output voltage, the transistor works in the amplification region, which will consume power itself. The high conversion efficiency of switching power supply is one of its great advantages, and because of its high working frequency, it can use small and light transformers, so switching power supply will be smaller and lighter than linear power supply.
Switching power supply is better than linear power supply if high efficiency, volume and weight of power supply are the key considerations. However, switching power supply is more complicated, and internal transistors will be frequently switched on and off. If the switching current is not handled,