How to choose a power adapter? What are the parameters of its operation?

Main working parameters of power adapter:

1. Input voltage and input current;

2. Output current and output current;

3. Output connector (interface) and output polarity (basically different brands have their own standards);

Generally, notebook adapters are 110-240V input, in line with global international standards.

When purchasing a power adapter, follow the following rules:

1. The principle is to choose the same brand and type, if not, it can only find other brands;

2. The output voltage of the power adapter is best equal to the voltage required by the notebook, if different, then as close as possible to the required voltage of the notebook, controlled within the error of ±5%, this is because the notebook inside the voltage regulator circuit generally has a margin design, in a certain range of input voltage changes, can work normally and stably; Beyond this range, the voltage is too low, the computer may not work steadily or even light up the machine; If the voltage is too high, it may burn out the voltage regulating circuit inside the computer. An Acer laptop, for example, requires a 15V, 3.36A input, but it works perfectly with an IBM 16V, 3.36A adapter.

3. The maximum output current of the power adapter should be consistent with the maximum current required by the notebook as far as possible. If different, it should be equal to or greater than the required current of the notebook; Note: As long as the current is large, you don't have to worry about how big, no matter how big, don't be afraid, don't worry about burning the machine! But the current should not be too small, because the screen flashing and other unstable conditions may occur. For example, the IBM T30 adapter (16V, 4.5A), although it is safely used on the IBM ThinkPad T20(16V, 3.36A), can also be used on the ThinkPad X31(16V, 3.5A); The principle is: the power adapter is based on the load to adjust the output current, not static.

Like the IBM 16V, 4.5A power adapter above, it can deliver up to 4.5A operating current, but with the T20, it only delivers up to 3.36A current. In fact, due to the different working conditions of the laptop, the current it needs is also in constant change, the adapter according to the working conditions of the notebook at any time to adjust the output power, to meet the needs of the computer. The adapter with a higher output current is more flexible, which is a bit of a "kill a chicken with a knife". However, the reverse is not good. Although the T20 adaptor can light up the T30, the T30 screen sometimes flickers because the T20 adaptor cannot provide the consistent operating current required by the T30.

4. The last point should have been in the first place, that is the power adapter output interface and output polarity (pay attention to the positive and negative poles) problem, you have to ensure that the purchase of the adapter can plug into your laptop, otherwise even if the working parameters are exactly the same, but you can not plug in, what is the use of you. Due to the independence of the major notebook manufacturers, the adapter adapters of different brands are different. The adapters of different series of notebook adapters of the same brand generally have the same specifications, but sometimes different brands may also use the same interface.