Why do poor quality power adapters leak electricity?

Many people are asking what is the reason for the power adapter leakage? There are several reasons for this, the first is the static electricity, and a safety standard in the safety standard, which is the safe leakage current in professional terms. If it is a non-mandatory product The AC leakage of the non-safety power supply certified to the safety standard is also very dangerous. In the past, there were often news reports that the power supply caused fires or personal and property safety accidents. It was this kind of non-mandatory product certification safety standard. Yes, so the author especially emphasizes that please use a safe standard power adapter.

If your notebook case is metal, when the ground is very wet, when you step on the wet ground with bare feet, you will feel numb when you touch the metal part again, and touch the metal part of the notebook again for a short time In fact, it is static electricity. But as long as you do not touch the wet ground with bare feet, you may rarely encounter such a situation. In fact, even the original power adapter of the notebook, if the ground is wet, if you use a Insert the root metal into the positive part in the middle of the DC head, step on the wet ground with bare feet, and touch the positive pole with your hands will actually feel numb, because many notebooks use a DC voltage greater than 15V for power supply. Then in such a special This will also happen if you touch it under normal circumstances. So this is why the DC head of the power adapter is the reason why the DC head of the power adapter is negative inside and positive outside. As long as it is not the kind of AC leakage but only static electricity, it is quite normal. And everyone also Don’t deliberately make the ground wet. And step on the wet ground with bare feet to touch the DC positive part with your hands.

In the special situation mentioned above, it is generally not encountered such a situation. Of course, the static electricity of electronic products is unavoidable, just as our human body will also be charged with static electricity in autumn and winter. When we take off the chemical fiber When wearing a sweater, I often hear the sound of “crackling”. If you are in the dark, you can still see small sparks on the clothes. If there is a ground on the power strip, the basic power adapter or other electronic products will basically not There is a situation of static electricity. Let’s talk about several situations in which electronic products are charged with static electricity:

1. There is a small amount of current inside the electronic product through the metal shell, which is felt by the human body as leakage. This situation has been solved well now that the technology is developed, and a loop will be formed inside the electronic product, and the static electricity is very Well, it’s released, so it’s almost never there unless it’s a special case.

2. The AC plug of the power adapter of the electronic product is not well grounded. If there is a leakage phenomenon in the contact with the electronic product, you can also do a simple inspection first. It is to connect a wire to the ground. Of course, you can also find An indoor drain pipe, connect a wire from the drain pipe to the shell of the metal part of the electronic product, so that the static electricity on the shell of the electronic product can be effectively introduced into the ground and released. When replacing electronic accessories, when removing them by hand Touching the floor card may cause damage to the accessories, and the static electricity of the human body will cause the display or printer to work abnormally, so it is best to mold the surrounding metal objects first to release the static electricity from your hands. It is best to wear clothes that are not prone to static electricity. shoes and clothes.

3. In fact, when the positive part of the DC power supply of the power adapter is touched with the practical hand, and the hand is relatively wet, and the human body is also in contact with the wet ground, the greater the DC voltage, the more obvious the numbing induction. In normal conditions Under the circumstances, this situation will not be encountered, which will especially make the ground and hands wet. And step on the wet ground with bare feet to touch the positive part of the DC power output of the power adapter. And even if it is safe, it must be reminded , do not imitate!

What we are talking about above is the electrostatic phenomenon of regular power adapters, not the situation of AC electric shock. In addition to static electricity, there is another technical parameter in the terminology of electronic technology, that is, leakage current, also known as leakage current.

In household appliances, leakage current refers to the safe current between the running electrical part and the metal after insulation. The leakage current of electrical appliances used for 220V AC is 0.25mA. This safe leakage current is very small. Leakage current refers to when there is no In the case of voltage applied by a fault, the current formed between metal parts with mutual insulation in the electrical system, or between live parts and grounded parts, through the surrounding medium or insulating surface is called leakage current. Leakage current is divided into four types , respectively: semiconductor component leakage current, power supply leakage current, capacitor leakage current and filter leakage current.

If the power adapter or other electronic products have unsafe static electricity, electric shock beyond the safe leakage voltage, or unsafe leakage current, which cannot be identified by ordinary consumers, the author recommends that you stop using it and contact the manufacturer. , and find out the specific reason.

In addition to the static electricity and leakage current described above within the scope of safety standards, there is also the AC leakage of non-safety power adapters, which is very dangerous. Non-safety power adapters have removed many safety components in order to save costs. Devices, such power adapters are in conduction radiation, and many other safety standards are completely unqualified. Non-safety products have potential safety hazards, and non-safety switching power supplies are exposed to dust, humidity, high temperature, lightning , vibration and other situations are prone to short-circuit phenomenon, once a short-circuit occurs, non-safety power supply is very likely to cause electric shock and fire, it is strongly recommended that customers choose non-safety power supply carefully for their own brand reputation and the safety of end customers’ personal property, so as to avoid irreparable damage loss.