With the progress of science and technology, the power of notebook power adapter is also getting higher and higher. Generally, it will generate high heat when working. In fact, this is normal. It needs to work. To convert the output electricity, it will consume energy, and some of it will become heat energy! It also depends on whether you have installed the battery or whether the battery is normal. The laptop power adapter is actually a high-precision and high-efficiency switching power supply, which is used to convert 220v AC mains power into low-voltage DC power, providing stable power for the normal work of the laptop. As long as the temperature of the power adapter is within the design range, that is, the temperature is within the normal range, there is generally no danger.

1、 So, what factors cause the heat of the power adapter?

The load of the power adapter (such as the built-in DC/DC conversion circuit, high-voltage board circuit, backlight circuit) has poor characteristics, or a component is damaged or invalid; Among the above circuits, the power regulator and filter capacitor are most likely to fail; These vulnerable parts will lead to a sharp increase in the invalid current (such as leakage current), thus reducing the dissipation power output efficiency of the adapter. The adapter has to output more electrical power to meet the electrical power demand of the whole machine, so the high heat condition occurs.

2、 Causes and solutions of IC over temperature

- Internal MOSFET loss is too large

The switching loss is too large, and the parasitic capacitance of the transformer is too large, resulting in a large cross area between MOSFET opening and closing currents and Vds.

The solution is to increase the distance of the transformer winding to reduce the interlayer capacitance, just as when the winding is wound in multiple layers, a layer of insulating tape (interlayer insulation) is added between layers.

- Poor heat dissipation

A large part of the IC's heat depends on the copper foil on the PCB and its pins. The area of the copper foil should be increased as much as possible and more solder should be applied

- The air temperature around IC is too high

IC shall be located in a place with smooth air flow and away from parts with too high temperature.

3、 Tips for solving the heating of 12V power adapter

1. Low ambient temperature

When using the power adapter, try to put it in a cool indoor place. If possible, place ice bags and cold compresses around it. When placing ice bags or water bags, pay attention to keep a certain distance to avoid water wetting the power adapter.

2. Fast air flow

Place a fan around the power adapter, or directly place the power adapter in a place with good ventilation effect. In this way, the heat dissipation will be much faster than usual.

3. Large heat dissipation area

This method mainly refers to the selection of switching components with low voltage drop and low loss, and the heat dissipation area should be as large as possible. Generally, switching power supplies above 100W should have metal perforated shells. When using, do not cover the power adapter with some objects, such as clothes or books. You can place the power adapter sideways to increase the heat dissipation area, and place some plastic or metal pieces under the power adapter on tiptoe. These methods together will have a much better effect.