Posted on 07/11/2017 8:47:48 AM PDT by Timpanagos1
A 14-year-old Texas girl died Sunday morning after she was electrocuted while using her cellphone in the bathtub, according to family members.
“This is such a tragedy that doesn’t need to happen to anyone else,” Madison Coe’s grandmother, Donna O’Guinn, told KCBD. “We want something good to come out of this as awareness of not using your cellphone in the bathroom as it is plugged in and charging.”
(Excerpt) Read more at statesman.com ...
“It only takes 0.1 amps to be fatal.”
She was not killed by the charging voltage/current of the charger. There are number of reasons why that would not happen in this case. But I won’t go into the science of that. Just remember there is a thing in this entire situation called Resistance that limits the current very much in a low voltage situation.
And also remember her hand was burned.
This girl was killed by AC line voltage. I don’t have knowledge of the the details of the charger So It makes it difficult to nail for sure. But most chargers these days are switching power supply’s. This means no transformer isolation from the 120 volt AC supply. This means that while the voltage between the two wires at the connector that plugs into the cell phone could be 5 volts or less there can still be the potential to kill. Because the voltage between either of the wires and ground can still be around 120 volts. Anyone creating a path between that 120 volts and ground is in for a shock. This is exactly the type of situation that GFI outlets were designed to protect from. They detect that current that should be flowing back through the outlets neutral is actually being lost via another path- most likely to ground.
In any case this was obviously caused by line voltage and line current. She would have been saved either by a GFI outlet or by an analog power supply using a line isolation transformer(assuming she did not contact Where the charger plugs into the AC)
Remember all the power power supplies with with the big black box that plugs into the wall. Those contain transformers that will isolate the output from the AC line voltage and make them safe from this situation.
When a person is wet all over, the electrical resistance of the skin is really low. Resistance in the blood stream, a salt water solution, is already pretty low.
Bathtubs/showers and electrical apparatus has always been known to be a bad mix.
I don't think that is what did it, simply because the wall wart is close to the wall with only a 5V lead into her phone. Wet all over, her body had a significantly reduced electrical resistance giving an easy path into her blood stream, which is largely salt water. I suspect water ran down her hand, down the cord, and into the connector. The 5V apparently did push up to .2 amperes into her nervous system, which is all it takes to kill someone.
Dry skin exhibits over 300,000 ohms of resistance. Wet skin, maybe a hundred.
I think she plugged her phone charger into the extension cord while she was in the tub, that will do it right there quick.
I don’t recall that math question being asked at DeVry.
MURDER.
Next....
MURDER.
Next....
I’m glad a little girl’s death can bring you so much amusement. Makes it all worthwhile.
I doubt she was taking a salt water bath.
.2 amps at 5 volts doesn’t have much force to make it into your body.
You have a point but the 5 Volts you refer is a Direct Current source.
If the resistance between two locations on her body were 25 Ohms then 1 watt of DC power of heat is applied.
I am inclined to think there is more to this story and I don't think 5 VDC can harm the nervous system such that it doesn't recover.
Taking a bath with a toaster will do the same thing.
Why do they find writers who are idiots.
If its plugged into the wall, don’t take a shower with it.
Especially when they finish with: “We have to make sure that something like this never happens again.”
I was referring to the saline content of blood, which there surely was enough in her to make a full-body connection.
.2 amps at 5 volts doesn’t have much force to make it into your body.
Voltage is the "force". Current is the "amps". Resistance is the load. Given the equation: V = C X R, or C = V / R, there will be a .2 amp current in the load at 5 volts when the resistance is 25 ohms. A current of .2 amps will kill a person. Normal skin resistance is 300,000 ohms or so. Wet, well, not so much.
It isn't the voltage that kills, it is the current. The threshold for death is 0.2 amps. That would be achieved at five volts if her resistance was 25 ohms.
I think she got the 120V in the other side of the charger.
Where?
From one finger to another finger or on the surface of the skin. Where would .2 amps driven by a potential of 5 VDC kill? Read up on how the human body reacts to DC currents.
Dear one, I am well aware of all of this stuff. A .20 amp current through the heart will kill it. Water on the skin significantly reduces skin resistance. From the skin on her hand into her blood stream or nervous system should be more that 25 ohms, but was it? Once in the blood stream, the electrical resistance would be quite low due to the electrical nature of the nervous system and the electrolites in the blood. The exit point from her body was basically the entire surface area in the water. That would be a parallel resistance, quite low for that large surface. That is a clear path through the heart.
Now, it the phone was plugged into its charger, water could have run down her arm, down the cord, and into the charger. That could have made a connection to the 120V AC of the electrical outlet. Given the electrical path previously discussed, we would find that something well over 25 ohms would pass .2 amps, like 600 ohms by computation.
Here is another scenario that wasn't discussed. Suppose she actually got zapped by the RF from the cell phone. If the tower was far away the phone could be using up to 5 watts of RF power. Given a nice wet path through her head into the drain, I give that a good possibility.
All of my posts taken together convey a lot more information than yours.
Adding the AC component to your thinking made your opinion plausible.
However, your last opinion regarding electrocution by received RF from a nearby transmitter left me pondering.
I do agree your posts conveyed far more information, at least more about your thinking.
Are you going to tell me that RF can’t hurt anyone?
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