Although the size of the power adapter is small, it is a sparrow. Although it has all kinds of internal organs, there are still many internal components. Today, let's introduce the internal components and functions of the power adapter.
1: The function of varistor is that when the external voltage is too high, the resistance value of varistor quickly becomes very small, and the fuse connected in series with varistor is blown, so as to protect other circuits from burning out.
2: The fuse is 2.5a/250v. When the current in the circuit is too large, the fuse will blow to protect other components.
3: The main function of inductance coil (also known as choke coil) is to reduce electromagnetic interference.
4: Rectifier bridge, d3sb in specification, is used to change 220V AC into DC.
5: Filter capacitor, 180uf / 400V, is used to filter the AC ripple in DC and make the circuit work more reliably.
6: Operational amplifier IC (integrated circuit) is an important part of protection circuit and voltage regulation.
7: The temperature probe is used to detect the internal temperature of the power adapter. When the temperature is higher than a certain set value (the set temperature threshold of different brands of power adapters is slightly different), the protection circuit will cut off the voltage output of the adapter, so as to protect the adapter from damage.
8: High power switch tube is one of the core components of switching power supply. Switching power supply can work "on and off", and the power of switch tube is indispensable.
9: Switching transformer is one of the core components in switching power supply.
10: The function of secondary rectifier is to change low-voltage AC into low-voltage DC. In the power adapter of IBM, the rectifier is often operated by two high-power in parallel to obtain a larger current output.
11: There are two secondary filter capacitors with the specification of 820uf / 25V, which can filter the ripple in low-voltage DC. In addition to the above components, there are adjustable potentiometers and other resistance capacitance components on the circuit board
