Linear power supply mode and switching power supply mode

The power supply circuit is an important part of the motherboard. According to its working principle, the power supply circuit can be divided into linear power supply mode and switching power supply mode. So what is the difference between these two power supply methods? The following is a detailed introduction by Caixing Electronics, a Guangdong linear power supply manufacturer.

1. Linear power supply mode
This is how motherboards were powered many years ago, by changing how well the transistors conduct. The transistor is equivalent to a variable resistor, which is connected in series in the power supply circuit. Because the same current flows through the variable resistor and the load, it consumes a lot of energy and causes the temperature to rise, and the voltage conversion efficiency is low. Especially in power supply circuits that require large currents, linear power supplies cannot be used. At present, this power supply method has been eliminated.
2. Switching power supply mode
This is the most widely used power supply method. The pulse width modulation controller integrated circuit chip provides pulse width modulation and sends out pulse signals, so that the field effect transistor 1 and the field effect transistor 2 are turned on in sequence. Chokes L0 and L1 are used as storage inductors and form an LC filter circuit with connected capacitors.