Can charging a phone in the bathroom kill you

You've probably often seen in the news headlines that in one country or another, a person died from electric shock while talking on a cell phone in the bathroom.
The phone was naturally connected to the charger in the nearest outlet. In general, with the advent of fully waterproof smartphones, such cases have only become more frequent.

If previously a person was stopped by the fear of ruining his gadget by dropping it in the water, now they are not afraid of this either.

For many who are ignorant of electrical engineering, a logical question arises: “How is this even possible?” It is well known that USB charging produces a voltage of only 5 volts.

At the same time, according to safety regulations, wiring up to 42V is allowed even in high-risk areas! How can regular exercise harm a person?

Ohm's law in the bathroom

The thing is that the USB charger does not always produce this same 5V. And under certain circumstances, the charging voltage may jump. To understand the reason why a charging smartphone can kill a person in a bath, you will have to remember the school physics course, namely Ohm’s law.

This formula is almost fundamental for all electrics. According to it, the current in the circuit directly depends on the applied voltage and is inversely proportional to the resistance. That is, the higher the voltage and the lower the resistance, the greater the current.

By analogy with our case, this formula can be translated into the following visual relationship:

Let's start with the cause of death first - current. Yes, yes, it is the current that kills, not the voltage. At a certain amount of current, cardiac fibrillation and paralysis occur.

What current should this be? Here is a table widely known to all electricians:

Guaranteed to kill a current of 100mA. But this is under normal conditions. For a person lying in a bath, in a certain situation, a value of more than 30 mA is quite enough.

Therefore, in electrical panels for human protection, it is most often a 30mA RCD that is installed.

Although for the bathroom, experts recommend installing residual current devices with a current of 10 mA.

Anything higher (100mA, 300mA) is considered primarily fire protection. And it is better not to install such RCDs on sockets.

At a current of more than 30 mA (even constant), your muscles begin to involuntarily contract, breathing becomes difficult and you can simply drown in the bath. Therefore, we will proceed from this calculated value.

That is, we will assume that if the current from the charger exceeds 30 mA, the bath will automatically turn into an electric chair.

Some attentive users who read all sorts of inscriptions on devices will pay attention - how can this be, the power supply clearly states that at 5V it produces a current of as much as 2 Amperes!

This means, according to the above sign, such a thing should outright kill anyone. But the fact is that the current in a circuit is not a cause, but an effect. What is indicated on the power supply is its maximum possible value that it is capable of delivering without harm to itself. That is, roughly speaking, it will not burn out and will work properly for a long time.

And what kind of current will flow through the person? Exactly the value dictated by Ohm's law. It will depend on human resistance and the voltage supplied by the power supply.

What's next

Depending on the situation, you can either call for help or leave the scene of the confrontation. Another option would be to apply a Taser to the criminal and hold him down. Threatening repeated use to force him to lie face down with his hands behind his back. After this, you can call the police and wait for their arrival.

The discharger should not be used in the head or neck area; it should be used with caution against elderly people. When using it in rainy weather, you should aim at exposed skin, as the arc can pass through a layer of water on clothing and not cause harm to the target.

Press the stun gun tightly against the attacker to reduce the amount of air in the folds of clothing; it can act as a dielectric, preventing the arc from passing to the desired location.

Human body resistance

Our body is primarily not muscles, but water, which conducts electricity remarkably well. But this water is securely hidden under the skin, the resistance of which is very high. And moreover, in different places for different people, the data will be very different.

For example, the resistance between the dry palms of a person can reach 10 mOhm (ten megohms). This is a very large value.

But if you increase the contact area, then this same resistance immediately decreases hundreds of times.

In addition, if there are any wounds or cuts on your body, this will reduce your protection several times.

This is the same as an insulated wire that will have an accidental cut from a knife in one place. Same with your skin. With any leakage, all the current will rush to this point.

Now imagine a bath where your wet, soft body is completely in contact with the water. How much resistance do you think it will have?

To avoid guessing, this matter can be easily measured with a multimeter. Of course, the result in each case will be individual, but it will not deviate greatly from the overall picture.

Just when taking measurements, do not repeat the experiments of Darwin Award winners.

As they say, a US Navy sailor once decided to measure his “internal resistance” without the error that the skin gives.

To this end, he purposefully pierced his fingertips with the sharp probes of a multimeter and received a fatal blow from just a 9-volt battery. The link to the English-language source of this case is here.

In the bathroom, we will measure the resistance between the drain and the hand.

When you put your hand in the water, the numbers show a value of about 1 kOhm.

At the same time, do not forget about the presence of calluses and roughness of the skin. For girls who take better care of their hands than guys, this resistance is even lower.

And all this provided clean water. In a situation with dirty or soapy shampoo, the measurement data will differ significantly. But we take ideal conditions.

Based on all this, for further life-threatening tests, we replace the conditional human body with a 1 kOhm resistor.

Of course, it does not fully take into account the real components of the resistance of the human body, but this option is also suitable for understanding the process itself.

Substituting the obtained data into the formula, we observe the following proportion:

That is, in order for a current of 30 mA to flow through a person lying in the bathtub, the voltage, according to Ohm’s law, must be equal to only 30 Volts.

Is it possible to kill an animal with a stun gun?

Most often, a conventional stun gun is used to scare away stray, aggressive dogs.

A loud, unpleasant sound, sparks, and the smell of ozone can really drive your dog away from you, without having to have close contact with it.

However, when attacked by an aggressive animal, there is an option to hit the head or nose with a stun gun; if the device is powerful enough, this blow will be fatal for the dog.

The effect of any stun gun is tolerated by animals heavier than humans. There are known cases when even bulls or orangutans were stunned with the help of a stun gun.

There are stationary high-power electroshock devices that are used on farms and households for slaughtering livestock or poultry.

This shocker can easily kill both a chicken and a large pig by attaching electrodes to the animal’s head.

Expert opinion

Viktor Pavlovich Strebizh, lighting and electrical expert

Any questions ask me, I will help!

narcotic mix drugs are often consumed with alcohol or mixed with opiates Heroin, Methadone, Morphine to enhance the effect;. If there is something you don’t understand, write to me!

How many volts can a charger produce - dangerous blocks

And here the most important question arises. Where does this voltage come from in the charger, which clearly says 5V? To begin with, it doesn’t hurt to remember the design of the power supply.

All modern chargers are pulsed. Very roughly, their diagram can be represented as follows:

The 220V mains voltage is rectified by a diode bridge and smoothed out by various filters. The result is a very high and constant voltage.

Next, this voltage is converted into a high-frequency signal using a cascade of transistors and supplied to a pulse transformer. A decrease occurs in it and through another filter we get at the output those same constant 5V.

And we are not yet considering modern devices with so-called fast charging. Their voltage, which the power supply produces when the phone is almost completely discharged, is not 5V at all.

There are several standards, and they are all based on the fact that at the initial stage, charging either increases the current or the supplied voltage. And at times. For example, Qualcomm Qiack Charge technology can charge up to 20 volts!

But we will still look at standard 5 volt devices to show you that they are dangerous too.

The high-voltage part of the charger circuit is galvanically isolated from the low-voltage part using a pulse transformer. The wires are connected to each other only inductively.

It turns out that high voltage should not get into the low-voltage part. With two BUTs:

if the insulation is not damaged

if the power supply did not fall into a puddle

In the case of the bathroom, we don’t even need a puddle.

High humidity and condensation greatly reduce the insulation of the entire circuit. And in the charger transformer, there is not always a layer of adhesive tape or electrical tape between the turns of the primary and secondary windings.

If one winding is simply wound on top of the other, then only a layer of varnish a few microns thick separates them. And if there is overheating or impulse noise in the network, there is a high probability of breakdown.

It is also worth considering the influence of flux, which often remains on the board after soldering. Acid flux, when water comes into contact with it, forms an electrolyte that conducts current well.

Besides all this, there is one more element of the chain. This is a capacitor that connects two windings to each other. It is necessary to suppress interference, and the safety of the entire power supply depends on its quality.

A low-quality capacitor can break completely, and then the mains voltage will leak to the low-voltage side.

You see how many dangers are hidden in this small block.

Rospotrebnadzor spoke about the onset of severe consequences with omicron: Society: Russia.

It's time to work on mistakes

The mass of deputies is not at all homogeneous. Reasonable arguments by opponents of dog-loving “extremists” have been heard before and continue to be heard now. Deputy of the Novosibirsk City Council, head of the Ministry of Health and Human Rights "Civil Patrol" of Novosibirsk Rostislav Antonov counters these arguments with data from established practice:

I tracked statistics for many regions. And everywhere the situation is only getting worse. And in the Kemerovo region, and in Chelyabinsk, Vladivostok, Perm, there is an increase in statistics of attacks by dog packs on people. Moreover, according to the law, chipped dogs have a certain indulgence. Nobody catches them again. And they are still aggressive.

The public organization is receiving complaints from all over the country. Experts and advisers to the “patrol” clearly believe that it is necessary either to return to the methods of the Soviet Union, or to analyze and apply the experience of European countries.

I would understand if the State Duma were suddenly seized by stray dogs and adopted this law for themselves. But his people voted. Although it is obvious that it violates the very logic of the legislative process. He doesn't protect people. He protects homeless aggressive dogs,

According to the deputy, if legislators made a mistake, then it needs to be corrected. Keeping wild dogs in cages for the rest of their lives is inhumane. Perhaps legislators should expand the list of indications for euthanasia beyond those incompatible with life.

If this turns out to be impossible, according to Rostislav, you can think about creating special, securely fenced areas where chipped and sterilized packs will live out their canine lives.

Bath experiment

To check all these assumptions, you can simply measure the voltage between the output from the charger and the ground, that is, the bathroom.

Even if you take completely different models in price category, most of them will have this voltage above 30 Volts. And some even reach 80!

Is the mortal danger of power supplies really so easily confirmed? Not certainly in that way.

If we add to the same circuit the resistance that our body has immersed in a bath (R = 1 kOhm), then we get a completely insignificant current value of a couple of hundredths of a milliampere.

This is more than a thousand times less than the dangerous threshold. What does this mean - Ohm's law has stopped working? Where did our 80 volts go?

The fact is that when the circuit with the resistor is closed, the voltage immediately drops to negligible values (about 1 V). Because that hole in the protection of the power supply, through which the mains voltage “flows” from us, does not allow a large current to pass through, and the voltage, according to Ohm’s law about the complete circuit, simply decreases.

This means that a working dry charger with a capacitor of normal quality is absolutely safe.

Even the Chinese are now trying to install normal capacitors. And when it fails, it simply turns into a circuit break. But if you come across a “cheap” model and the capacitor turns into a jumper due to a malfunction, then a quick end will come both to the charging smartphone and to you.

This can happen, for example, during a thunderstorm. When lightning strikes a power line several kilometers from your home, an overvoltage pulse will travel along it, which, upon reaching the outlet, will set your charger on fire.

Protection against this has long been invented in the form of an SPD. But for some reason, such protection devices are not yet as widespread as the same voltage relays or RCDs.

But returning to “our sheep” - if all the elements are intact and nothing goes wrong, what then can kill? A simply wet charger kills.

At the same time, a damp board from condensate, which is essentially a distillate, is not yet so dangerous. The current here is unlikely to exceed the minimum threshold of 30mA.

But if splashes of water get directly into the body, then expect trouble.

In this case, a current of dangerous magnitude will pass through the charger, your body, the bathtub and go into the ground.

Knockout Punch

Those who have recently purchased a product usually have the same question: how to “knock out” a person with a shocker, is it possible to do this. This result can be achieved if you have at your disposal powerful models of paralyzers, like those presented below.

Zipper YB-1120. The real weapon of Zeus. 100,000 volts inside a heavy baton will not leave anyone indifferent. They will clearly convey your message to your opponent. . Not as powerful, but still strong enough to stun an aggressor, a 50,000 volt device. . Looks like a flashlight, hits like a middleweight boxer, reliably knocking out an attacker.

In order to achieve loss of consciousness of the target, it does not matter much where to hit with the shocker. Only the exposure time matters. Have courage and don't give up. Having come into close contact with the individual attacking you, firmly apply the spark gap to him and press the button, hold it for at least 1-2 seconds.

A shorter impact will lead to muscle spasm and painful shock with preservation of consciousness; when impacted for more than a second, loss of consciousness and deep shock occurs. The vision becomes dark and complete disorientation occurs. The attack on you stops.

Expert opinion

Viktor Pavlovich Strebizh, lighting and electrical expert

Any questions ask me, I will help!

physiological characteristics, current enters the human body through the channels of the sweat glands of the skin, therefore the conductivity of the body depends on their number and intensity of activity;. If there is something you don’t understand, write to me!