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Why do phone chargers hurt people?
Oct 11, 2018

Why can the mobile phone charger hurt people?

The incident of mobile phone charger has been happening many times. Why is the mobile phone charger hurting people? One common point of such incidents is that they have one thing in common - they all happen when charging!

The voltage of the mobile phone lithium battery is generally about 3.7 volts, which is almost one tenth of the safe voltage of 36 volts, but it is not necessary to charge, although the probability is extremely low!

The power adapter converts 220 volt AC in a household circuit into a 5 volt, 1 amp or 2 amp DC, and then outputs it to the phone via a USB cable. A qualified mobile phone charger isolates the dangerous 220 volt home circuit voltage from the safe voltage of the USB output port of 5 volts by reinforced insulation or double insulation.

Therefore, under normal circumstances, the voltage from the power adapter into the phone charging line is only 5 volts. We know that the safety voltage is not higher than 36 volts, the continuous contact safety voltage is not higher than 24 volts, the safety current is no more than 10 mA for AC power, and the direct current is not higher than 50 mA.

However, the charger failed, mostly because of its own quality problems. Inferior chargers that are inexpensive but not good are likely to have serious design flaws. For example, the protection device of the power adapter may not be closed, or there is no protection device. In case of failure, 220 volts may be directly output to the mobile phone. At this time, if a person touches the broken charging wire of the insulation, and another part of the body touches the conductor to form a loop, the electric shock is reached! For example, some cottage chargers do not use flame retardant materials, and the charging time is long. It may also cause a fire.

Therefore, in those cases where the charging was electrocuted, it is very likely that the power adapter of the inferior charger failed, and the human body directly touched the 220 volt power and formed a loop...

How to avoid such incidents from happening again

Try not to use your phone while charging. Whether it is calling while charging, playing with a mobile phone while bathing, or hitting a broken charging cable while sleeping, people are exposed to the phone or charger when charging. Therefore, as long as you do not touch them when charging, far away, it is absolutely impossible to get an electric shock, and in order to avoid a fire, the phone should be placed in a well-ventilated place, away from combustibles

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