Why 12 volts.

[History]

Only 50v to kill cows. Shows how dangerous even such a relatively low voltage can be.

The body does have resistance. Enough voltage and amps together is fatal. A jolt from ignition can kill and the amps is very low.

Fortunately most people when get a jolt aren't fully earthed rubber soles on shoes etc. But even a 110v shock if you are fully earthed is liable to be fatal.

I saw a you tube clip of a guy standing on a step ladder in a full swimming pool using a mains electric drill. He lived to tell the tale.

I remember a radio that had a lead acid battery for the heaters in the valves. And a 90v big flat dry cell battery from everready which was for the valve grids or plates.
I used to listen to sing something simple on the BBC light program. Now Radio 1.

Bob

[TerryG]

I have been thrown back by 240v that some idiot (who was subsequently sacked) wired up to a 24v entryphone. Still alive fortunately but it really hurt.
Bizarrely it feels like someone has poked you really hard under the ribs on both sides and makes your mouth taste like copper.

[kstrutt1]

I have been thrown back by 240v that some idiot (who was subsequently sacked) wired up to a 24v entryphone. Still alive fortunately but it really hurt.
Bizarrely it feels like someone has poked you really hard under the ribs on both sides and makes your mouth taste like copper.

Isn't that the symptoms of a heart attack?

[History]

Heart attacks feel like ones chest is in a vice.

I had septic shock once and I couldn't stop shaking and the medics asked me where I thought I was I said Russia. I was actually in Bournemouth hospital, on kidney dialysis.

Electric shocks are quick and don't hurt as much.

The USA uses a domestic 2 phase system a 110v per phase. The lights would be on one phase and neutral at 110v. The sockets on the other phase and neutral at 110v.
A clothes dryer which uses more watts would be on both phases instead of one side being neutral both sides are at 110v. This gives 220v. 60Hz. An earth is used for safety.

This is much safer because children who stick their fingers in a table lamp bulb holder don't get thrown across the room. Because of only 110v.

Bob

[kstrutt1]

48v is supposed to be the next thing for new cars, this would be used for mild hybrids and high power electric items like a/c and electric turbos mind you it has been talked about for about 20 years and has not happened yet.
If I remember correctly below around 60v is safe because our bodies have too much resistance for any significant current to flow. The other issue is ac or dc, dc as used in hybrid and electric vehicles tends to be far more dangerous because you don't tend to get thrown away as you do with ac

[tractorman]

I think I prefer the UK system - the plugs are certainly safer as you can't touch the "live" part of the terminals if the plug isn't right in and the earth always connects before the live and neutral - and you shouldn't be able to stick your fingers in a socket unless there is something in earth's "hole".

However, with relatively modern systems, there should be an ELCB or similar unit installed (the newer systems require them on each circuit breaker). OK, some (like ours) is dual rail - one rail hasn't got an ELCB and does things like the immersion heater, cooker and door bell; stuff that you can't plug/unplug.

I was thinking of the old humbug about how dc is more dangerous than ac: it was said that dc made you grip tighter when you got a shock and ac "blew" you away from the cables! I gather it is a fallacy, though a friend swears it is true as it happened to him when working on a control system (many industrial systems have dc motors).

[zipgun]

My lathe gives you a fair old belt if its got condensation on it ..

[TerryG]

Entry phones explode when wired to 10x the voltage they are supposed to take and trust me, it REALLY hurt. Although that may be more to do with me hitting the floor than the electricity.