Advantages and disadvantages of switching power supply and linear power supply
Advantages and disadvantages of switching power supply
Main advantages: small size, light weight (the volume and weight are only 20-30% of the linear power supply), high efficiency (generally 60-70%, while the linear power supply is only 30-40%), strong anti-interference ability, output voltage Wide range, modular.
Main disadvantages: due to the high-frequency voltage generated in the inverter circuit, there is certain interference to the surrounding equipment. Good shielding and grounding are required. Alternating current is rectified to obtain direct current. However, due to changes in AC voltage and load current, the DC voltage obtained after rectification usually causes a voltage change of 20% to 40%. In order to obtain a stable DC voltage, a voltage stabilizing circuit must be used to achieve voltage stabilization.
Pros and Cons of Linear Power Supplies
Advantages: The advantages of linear power supply are relatively simple structure, small output ripple, and low high-frequency interference. The biggest advantage that the simple structure brings us is the convenience of maintenance. The difficulty of maintaining a linear power supply is often far lower than that of a switching power supply, and the maintenance success rate of a linear power supply is also much higher than that of a switching power supply. Ripple is the AC component superimposed on the DC stabilizer. The smaller the output ripple means the higher the purity of the output DC power, which is also an important symbol of the quality of the DC power supply. The direct current with too high ripple will affect the normal operation of the transceiver. At present, the ripple of high-grade linear power supply can reach the level of 0.5mV, and the level of general products can reach 5mV. Linear power supplies do not have devices that work at high frequencies, so there is almost no high-frequency interference/high-frequency noise if the input filter is done well.
Disadvantages: A huge and heavy transformer is required, and the size and weight of the filter capacitor required are quite large, and the voltage feedback circuit works in a linear state, and there is a certain voltage drop on the adjustment tube, which causes a large operating current when outputting a large working current. The power consumption of the adjustment tube is too large, the conversion efficiency is low, and a large heat sink must be installed. This kind of power supply is not suitable for the needs of computers and other equipment, and will be gradually replaced by switching power supply.
