Mobile phone adapter introduction

The power adapter is a power supply conversion device for small portable electronic equipment and electronic appliances. It is generally composed of a casing, a power transformer and a rectifier circuit. According to its output type, it can be divided into AC output type and DC output type; according to the connection method, it can be divided into wall plug And desktop. Since mobile PCs do not have batteries, power adapters are particularly important for them.

 

Types of power adapter

There are two main types of power adapters, switching power supplies and linear power supplies.

1) Switching power supply is a kind of power supply that uses modern electronic technology to control the time ratio of switching on and off to maintain a stable output voltage. The switching power supply of the power adapter is generally composed of pulse width modulation (PWM) control IC and MOSFET.

Advantages: high work efficiency, small size, and can work in a wide voltage range.
Disadvantages: Great interference to the power supply circuit, difficult to repair when a fault occurs.

2) The linear power supply transforms the AC power through a transformer, and the rectifier circuit rectifies and filters to obtain an unsteady DC voltage. To achieve a high-precision DC voltage for the power adapter, the output voltage must be adjusted through a voltage feedback circuit.

Advantages: This kind of power supply technology is mature, the circuit is simple, and there is no interference and noise of the switching power supply.
Disadvantages: The voltage feedback circuit works in a linear state, the power consumption of the regulator tube is large, the conversion efficiency is low, and the weight of the equipment is heavy due to the use of inductive transformers.