What type of shock is more dangerous

[kender]

danger ac vs dc

A high frequency AC signal would burn you rather than leading to fibrillation and death.

This effect is used for tissue ablation by medical devices. The frequency is usually 400-500kHz. The subject gets a warmth/heat/burn sensation, but there's no "electric shock" sensation and no muscle twitch. I've tested it on myself by touching the electrodes of a running device.

 

[hkBattousai]

do welders get electrocuted

A high frequency AC signal would burn you rather than leading to fibrillation and death.

This effect is used for tissue ablation by medical devices. The frequency is usually 400-500kHz. The subject gets a warmth/heat/burn sensation, but there's no "electric shock" sensation and no muscle twitch. I've tested it on myself by touching the electrodes of a running device.

Intresting. I didn't know about this. Why does high frequencies do such an effect, do you know the explanation? Maybe the nerve cells are behaving capacitive, and drain more energy at higer frequencies. Or the overall body drain more energy and get warmer.

 

[kender]

which is more fatal? ac or dc

A high frequency AC signal would burn you rather than leading to fibrillation and death.

This effect is used for tissue ablation by medical devices. The frequency is usually 400-500kHz. The subject gets a warmth/heat/burn sensation, but there's no "electric shock" sensation and no muscle twitch. I've tested it on myself by touching the electrodes of a running device.

Why does high frequencies do such an effect, do you know the explanation?

Here's my crude understanding*. Electric voltage depolarizes the neuron. For the neuron to "fire", it should stay depolarized for some finite amount if time. In case of high frequency AC (100kHz and above), the neurone doesn't stay depolarized long enough to fire.

I've also heard that the tissue has weak rectifying properties, so the applied AC can get rectified, and a DC component will develop. I haven't seen that myself yet.

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* I'll verify and update this in the next couple of days.

 

[hkBattousai]

effects on the body of a.c and d.c

Here's my crude understanding*. Electric voltage depolarizes the neuron. For the neuron to "fire", it should stay depolarized for some finite amount if time. In case of high frequency AC (100kHz and above), the neurone doesn't stay depolarized long enough to fire.

I've also heard that the tissue has weak rectifying properties, so the applied AC can get rectified, and a DC component will developped. I haven't seen that myself yet.

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* I'll verify and update this in the next couple of days.

This is an important detail. We should have some biomedical knowledge to talk about this, don't we?

And yes, "feeling warm" and "getting warm" are different things. Electric energy will effect neurons as well.

 

[insrusingh]

effects of a.c and d.c on the body

It is correct thet DC is more dangerous(much more dangerous than AC).Because if you get a shock from DC suppose 200V,100A then you will die but if that is AC it is pulsating so there is chance that you will be saved.

 

[xaccto]

dangerous dc voltage levels

lol, this topic got me wondering now, is the electric "chair" AC or DC to deliver the fatal stuff?

 

[hkBattousai]

which is more dangerous ac or dc

It is correct thet DC is more dangerous(much more dangerous than AC).Because if you get a shock from DC suppose 200V,100A then you will die but if that is AC it is pulsating so there is chance that you will be saved.

Tell us, just what makes you think that a pulsating voltage is less dangerous that DC voltage?

And if a human body lets 100A through for a 200V DC voltage, its ohmic resistance must be 2Ω.
(Being more precise, V(s) = I(s) . Z(s), where |Z(s)| = 2 for jw = 0)
Just what kind of a body could have such a low resistance? Do you consider humans same as fish or earth worms?

As I told above, don't gas out without knowledge in human biology, chemistry and circuit thoery.

 

[kender]

effects of ac electric on dc component

lol, this topic got me wondering now, is the electric "chair" AC or DC to deliver the fatal stuff?

Historically, the "chair" is AC. At the turn of a century in the beginngin of the electric era there was a cut-throat competition between Westinghouse and Edison. Westinghouse was pushing the AC, Edison was pushing the DC. At the same time, both of them had proposed a design of an electric chair to the government. Edison yielded the contract to Westinghouse. Westinghouse had built AC "chairs", but he got a lot of negative publicity. Immediately, Edison started a campaign claiming that AC is unsafe.

 

[Reuel2]

how much voltage is danger for human

Wow! Too many suppositions to read through them all!

Here are the facts.

AC is more dangerous. DC is continuous, and tenses muscles. AC alternates at a frequency (I'm assuming 60Hz) that is close to your heart rate. AC, when it causes fibrillation, does so because it interferes with, and destabilizes, the signals that tell your heart how often to beat. DC almost never causes fibrillation, so death by DC almost always involves either long-term exposure, preventing normal heart/lung operation, or tissue damage.

 

[ahsan159]

ac & dc effect on body

I do believe that AC is more dangerous that it cause more energy dissipations and the actual levels of AC are √2 times of the given value.

 

[hkBattousai]

which more dengerous shock due to ac or dc

Wow! Too many suppositions to read through them all!

Here are the facts.

AC is more dangerous. DC is continuous, and tenses muscles. AC alternates at a frequency (I'm assuming 60Hz) that is close to your heart rate. AC, when it causes fibrillation, does so because it interferes with, and destabilizes, the signals that tell your heart how often to beat. DC almost never causes fibrillation, so death by DC almost always involves either long-term exposure, preventing normal heart/lung operation, or tissue damage.

You are the fourth one (the other three: KoRGeNeRaL, MickDDnt and kender) who made an explanation which makes sense.
This topic made it clear that how little people know about electircal circuits and how much they talk about something they don't know.

"The one knows least, knows it the loudest."

 

[Sfp70]

Re: ac dc fibrillation

A DC of at least 30V is enough to kill. Remember dc hits you without a break. AC at least passes through zero!

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