The characteristic of linear DC power supply is that its power device regulator works in the linear region, and the output is stabilized by adjusting the voltage drop between the regulators. Linear DC power supply is named for its internal regulator operating in linear range.

The advantages of this kind of power supply are high stability, small ripple, high reliability, minimum peripheral components, minimum output noise and minimum static current. The disadvantage of this kind of power supply is that the voltage difference between input voltage and output voltage of linear DC power supply (commonly referred to as voltage difference) is large, the loss of regulator is large, and the efficiency is low.

The fundamental difference between switching DC power supply and linear power supply is that its transformer does not work at power frequency, but works in tens of kilohertz to several megahertz. The function tube does not work in the saturation and cut-off zone, i.e. the switching state; the switching power supply is named for it. The advantages of switching power supply are high efficiency (up to 80-95%) and stability and reliability. The disadvantage of switching power supply is large ripple (generally less than 1% VO (P-P), good can achieve more than ten mV (P-P) or smaller.

Advantages of Linear DC Power Supply
Linear DC regulator has the advantages of high stability, small ripple, high reliability and easy to be made into multi-output continuous adjustable power supply. The disadvantage is that it is bulky, bulky and relatively inefficient. From the output value, it can be divided into fixed output power supply, band switching adjustment and potentiometer continuous adjustment. From the output indication, it can be divided into pointer indication type and digital display type.

Advantages of Switched DC Power Supply
The switching DC power supply is a direct rectifier to obtain high voltage DC. The switching time ratio of the switching tube is controlled by the high frequency oscillator to adjust the output voltage. Switched power supply circuit is divided into two types: series and parallel. The advantage of switched DC power supply is high efficiency. Because the power consumed by the transistor under switching state is very small, it can reach 70-80% or even higher efficiency. Moreover, no step-down transformer is needed. Because the output transformer works at high frequency, its volume is far less than 50 Hz industrial frequency transformer, the switched DC power supply has the advantage of high efficiency. The power supply circuit is compact and portable, and can work normally in a large voltage range.

The difference between linear DC power supply and switching DC power supply is that switching DC power supply is a kind of DC power supply different from linear DC power supply. The fundamental difference between switching DC power supply and linear power supply is that the transformer in the circuit does not work at power frequency, but works in tens of kilohertz to several megahertz. Power transistor is not working in linear area, but in saturation and cut-off area, that is, working in the switching state, so switching DC power supply is named.