Electrocution: Are there any PSU's that provide mains voltage to a computer?

[Ignis Fatuus]

About 30 people in the UK die each year from mains electric shocks, with another 300,000 serious injuries. The painful twitch can be more of a shaking, and can also cause you fall or get locked on to whatever is delivering the shock, at which point you are ****ed unless someone detaches you. The one time this happened to me I was lucky and fell away from it rather than on to it.

Why don't you turn the power off and check it's off before you start?

Absolutely. It happened to me once only I did fall on to it and couldn't let go. My dad heard a thump from downstairs as I fell on the floor, and by chance I had actually mentioned to him that I was going to do something electrical, and god bless him he was not one to shrug his shoulders and let things pass - so he shouted up to me and when I didn't answer, he ran to the main board and switched off the house.

Or else I wouldn't be arguing this now.

Also, I seem to remember having read that if the shock starts at a precise point in the cardiac rhythm, the heart will stop instantly and that's that.

[Ignis Fatuus]

Anyone who thinks turning off the power makes something safe is bonkers. Even after unplugging, there is still a chance (an outside chance) that you can be zapped.
be careful out there.
And IF, IF, you ever have to touch or brush anything that has the remotest chance of being live, do it with the back of your hand and not the palm or fingers. A shock can make the hand go into a grip and lock you onto whatever is killing you. A zap to the back of the hand will make you move away pretty sharpish.

If you are sweating or otherwisw wet, take double care, and if you have a long pointy nose, dont stick it where it's not wanted

Good advice there. BTW numbers of appliances store a potentially lethal charge in capacitors. E.g. a microwave - never dismantle one to DUY.

[KentPhilip]

Absolutely. It happened to me once only I did fall on to it and couldn't let go. My dad heard a thump from downstairs as I fell on the floor, and by chance I had actually mentioned to him that I was going to do something electrical, and god bless him he was not one to shrug his shoulders and let things pass - so he shouted up to me and when I didn't answer, he ran to the main board and switched off the house.

Or else I wouldn't be arguing this now.

OMG!

[EternalOptimist]

vetran, there is a lot wrong with your post.

it's not the voltage that kills you, it's the current. and the current has to be in the right place. If you get a few amps across the hand, it may burn or blow you finger tips off, but it wont kill you. A tiny current across the chest or ears can kill you.
The resistance (ohms) of a human body can be very low indeed, so a low voltage can generate the required current. The biggest resistance in the body is the skin, so if you are wet, or have a wound, you are in much greater danger
and if you are ever going to touch something that may be live, use the back of your hand and put the other hand in your pocket or behind your back

[d000hg]

Thousands of people die on the roads but we still drive cars. If you do elctrical maintenance you will get a shock from time to time. In the same way you have a close call or an accident driving on a wet A road. Sh*t happens. If 240 volts was so dangerous it would be put down to 50 volts. The reason why it is 240 volts is because it is pretty harmless.

Nobody says cars are pretty harmless. That's why you have to take a test to show you can use one.

[BlasterBates]

Nobody says cars are pretty harmless. That's why you have to take a test to show you can use one.

Yeah which is the point I was making.

I mean drving down the motorway, taking your chain saw to a tree trunk, eating a can of beans (Botchelism) and having a hot shower (Legoinaires) all carry risks that we need to weigh up.

In comparison to most of the above using a voltmeter to check your PSU is pretty far down the list.

[EternalOptimist]

Good advice there. BTW numbers of appliances store a potentially lethal charge in capacitors. E.g. a microwave - never dismantle one to DUY.

not just capacitors, collapsing fields as well. And if they have nowhere to go, they can persist for quite a while
it might defy all common sense, but some appliances, when you pull the plug out, can suddenly become live at the pins on the plug. You put your fingers across them and you would sure know about it
I got into the habit , may years ago, of treating unplugged stuff just like plugged in stuff. with great caution

[BlasterBates]

Lets put it this way grabbing hold of a hot soldering iron is more painful than an electric shock and the experience isn't improved by the acrid smell of burning flesh

[vetran]

vetran, there is a lot wrong with your post.

it's not the voltage that kills you, it's the current. and the current has to be in the right place.

'less likely'

yes but to allow current flow through the heart from the extremities in most cases you need voltage.

but the link to wikipedia and the YMMV rider weren't enough.

[d000hg]

Yeah which is the point I was making.

I mean drving down the motorway, taking your chain saw to a tree trunk, eating a can of beans (Botchelism) and having a hot shower (Legoinaires) all carry risks that we need to weigh up.

In comparison to most of the above using a voltmeter to check your PSU is pretty far down the list.

You didn't say the risk of a shock was low. You said 240V wasn't very dangerous. So the comparison is not between using a chainsaw or changing a socket. It's between using a chainsaw or touching a live wire.

I'd rather grab a chainsaw than the mains.