Why does the 3.7v cell phone battery can kill people?

The battery voltage of mobile phone is 3.7 v. Why does the 3.7v cell phone battery can kill people?

Release date: 2017/11/26 read number: 0 author: report on the sidelines bully gas leak

News headlines you recently saw a horror:

A girl met during sleep is broken skin cell phone charging line, had been electrocuted!

The thing is...

According to England "daily mail" reported, a 14-year-old girl in Vietnam because met while they were sleeping, charging the mobile phone lines and electrocution.

Vietnamesespecial found in her bed charge line have burn out.

Mobile phone battery voltage is 3.7 v, why can electrocute people?

According to the report, this charging line is shorter, may not be original, wire insulation skin has been damaged the above also tied the tape.

The girl's unfortunate death is too sad and sorry. The mobile phone chargers really can kill? Headlines jun conveniently search on the Internet, there's plenty similar things.

Dear friends found? Although they are the cause of the accident is multifarious, but have one thing in common - are charging an accident!

Mobile phone battery voltage is 3.7V, why can electrocute people?

The lithium battery of mobile phone generally is about 3.7 v, the voltage is almost one over ten of the safety voltage 36 v, of course the undead. But not necessarily when charging, although the probability is very low! Please listen to me carefully say:

See the big plug?

Mobile phone battery voltage is 3.7 v, why can electrocute people?

This thing called "the power adapter, household 220 v voltage in the circuit can be alternating current into a voltage of 5 v, rated current 1 amp or 2 amps direct current (dc), and then output to the mobile phone through USB wire.

Mobile phone battery voltage is 3.7 v, why can electrocute people?

Qualified phone charger will by reinforced insulation or double insulation dangerous family circuit voltage 220 v 5 v safety voltage isolation with USB output port.

So, under normal circumstances, the electricity from the power adapter into the mobile phone charging line voltage will have only 5V. We know that the safety voltage specified in the industry is not higher than 36 v, continuous contact with safe voltage no higher than 24 v, safety current to an alternating current is not higher than 10 ma, dc is not higher than 50 ma.

Have a friend to ask the charger output current of the biggest to the 2A which is 2000 ma, is 40 times as much as 50 ma! Is such a big electric current electric immortality?

Indeed...Electric deathless, because the current is mobile phone charging current, rather than through personal current, principle is as follows. Left (not interested friends please skip oh)

The output current is used to recharge the phone current, according to the famous ohm's law --

I (current) = U (voltage)/R (resistance)

Small mobile phone charging system is the metal material, resistance good conductivity, so current is big, but the current again big and there is no direct relationship between the people of contact.

Through the body of the power flow is to calculate according to ohm's law, the human body is a conductor, but a much higher resistance than metal materials or. The human body resistance is not a constant value, it has to do with contact voltage, influenced by the environment, and different constitution of resistance is different also.

According to the data: generally in the dry environment, the resistance of the human body surface in about 2000 ~ 20 million ohm range; Skin is sweating, which is about 2000 ohms around; Skin wounds, which is about 800 ohms. Human body resistance is basically stable, which is about 500 ohms.

Even if we take the body to calculate the resistance of 500 ohms: 5 v divided by 500 ohms equals 0.01 amps, namely 10 ma, below the dc security current 50 ma this value.

So, under normal circumstances, whether in the cell phone charging, or by hand and mouth contact with broken skin charging line is not electrocuted.

This is a rumor, media has been rumour and friends can search

So, how they die? Murphy...

The key to!!!!

The quality of the charger is out of order, and mostly because of itself has a problem. And cheap but not good bad charger is likely to have serious design flaws, such as the protection of the power adapter device might not pass, or without protection device, once appear, fault, may be directly to mobile phone output voltage of 220V. At that time, people if touch skin damaged insulation charging line, another part of the body is exposed to the conductor to form a loop, get an electric shock! As another example, some fake charger without the use of flame retardant materials, charging time long internal components fever, and may cause fire.

The electricity dead cases before are most likely because there is a fault in the power adapter of inferior charger. Human body contact with the 220 v power directly, and formed the circuit...

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