I have a lot of stories about getting shocked. I have once got a little zap off a CCFL inverter. It didn't even tingle, but the plasma arc can give a bad burn. I somehow managed to get a tingle off an old Dell wireless NIC (I think it's the power for the RF circuits). I am currently working on a wireless modem for a remote control project, and those wireless modems can give an RF burn. A little more than a year ago, at a private group meeting, an old PC came in for repair (which wouldn't turn on). Kevin (who never worked a SMPS before) offered to fix it. He went ahead, and a few minutes later, he took the SMPS out of the PC, then proceeded to open it. He first saw a blown fuse (he said, "Oh, yeah, just a blown fuse."), which was a 5A slow-blow. He then replaced it with a regular 5A, only to find that the new fuse blew when he connected the power. The really funny part came when he took the board out, then proceeded to probe it with a cheap meter. POP! The meter was destroyed, and the probes had a good chunk blown out of them. He gave up, not wanting to get hurt. Christina Mahoney (the SMPS expert) then took a christmas tree bulb out of her purse, and safely discharged the big capacitors with it (the bulb lit up quite brightly for a few seconds). Then she replaced the fuse with a proper 5A slow-blow, and the SMPS worked on the first try! The PC was put back together, and it booted up fine! Kevin got laughed at for getting beaten (or should I say outsmarted) by a girl. My friend Mary was repairing a PC that doesn't boot up (it was an extra small desktop PC that uses a laptop CPU and GPU). I was doing my own work, when all of a sudden I heard a very loud thump. It turns out she got a shock from the high voltage capacitors, causing her to jerk her arm back violently. It was quite serious, too, as she actually broke her arm! Bottom line: Always discharge the high voltage capacitors with a christmas tree bulb before servicing or you may get hurt! P.S. The fault with the PC is an open startup resistor. Thus, the SMPS doesn't start and the capacitors retain almost all of their charge for a very long time.
usually higher voltage will have lower current but not always true. I've done AC voltage before, but also 1200 V from a cathode inverter, just in a fingertip. Burned my skin right black.
Never, ever work with live AC with both hands. Sounds silly, no? But think about it. Most of you have said they're surprised that they're still alive with a 240 volt shock. However, the current was only flowing through the path of least resistance through your body. If you happen to shock yourself on 240 VAC with one terminal in your left hand, and one terminal in your right, the path of current will flow through your chest, your heart, and coincidentally, your forearms, causing your grip to tighten. This unfortunate combination often causes death. Work with one hand, you still may get shocked, but at least it's not through a vital organ and you can let go instantly. Just my advice. Perhaps from experience. -silas
Exactly. If you ever watch a guy fixing a TV for instance, he will only use one hand while working inside the set. At least, that's what I was taught to do. Also, if your unsure if an AC circuit is hot, bring the back of your hand near it, but NOT touching. If the circuit is hot, the hairs on the back of your hand will stand up, kind of like touching the front of an old TV or monitor immediately after switching it off. A sort of static electricity effect.
yea like when i was puting in the power point to my new room i forgot to turn the power of at the switch i only got a little shock, since then i have got heaps of the psu im building and on my inverters (el string, cold cathode) they feal funny tom, but the worst was when i was woriong on the lines in our house, ill never use my teeth to strip another wire again (excluding dead wire)
Just a little shocking story. I built my cousin a computer that uses an old AT power supply and he abuses the hell out of it. He decided one day, to take the rubber pads off the bottom of the case and set it on his METAL!!! desk. Well, I sat down to do some work on it, turned it on, and put my elbows on the desk while turning on a lamp. I became path of least resistance and fired the lamp and pc. I have no clue how many volts, but my doc said it gave me a mini heart attack. hurt like all. Anyways the moral of this story is: Don't give my stupid cousin a computer.
add another story to the pile last summer i was mowing my neighbors feild behind my house for some cash with my electric lawn mower. the grass was covered in dew but i figured itd be fine to mow the lawn. NO, IT WASNT!! i was mowing the lawn and the plug disconnected (i was using 2 cords to reach) so i grabbed em both and plugged em in, my finger was over the plugs and the electricity arc'd into my hands. i stood there for a second or 2 feelin the tingle thinking "let go, LET GO" then finally let go. apparently i forgot this scenario and did it again 5 minz later. never done that since tho. Moral of the story: BUY A GAS LAWN MOWER! the electric is my moms choice, she likes it cuz theres no gas to buy, no engine to service. personally, id rather a gas engine any day.
Well people have lived getting stuck by lightning, and that's roughly a billion volts at some insane current (enough to make electricity jump a mile, no small feat). Of course it's the insane heat that comes as a result that really does you in. Of course easy solutions to both problems: unplug it before opening it and don't go out in a thunderstorm.
actually its because of the fact that if you grab a hot(enough) object with the palm of your hand your hand will close on it burning your hand further.
Also as an added benefit, smaller shocks can be more dangerous than large ones. Large shocks pick you up and throw you, usually disconnecting you from the source of the shock. A small shock, often will contract your muscles and hold you, causing you to stay connected to the source of the electricity. Just something to keep in mind...
I remember when i got my first bad shock. It happened on the way home from a School trip to Williamsburg, Va. On my bus (a greyhound type one, the ones with the bathrooms) someone ripped apart their disposable camera to try to get the flash to work with no luck. Well me being the only one on the bus with electronics knowlege i decided to give it a try. I took a fress AA battery that went into it and i put it in. Little did i know, my thumb was across a capacetor. I couldnt move, i was shaking. One of my friends saw me and knocked the camera out of my hand. I felt so weird and messed up. So i ripped the cap off the board and we threw it in the toilet. It sizzed, smoked and poped. I feel weird just remembering about it.
Hahaha done exactly the same, it was kind of fun actually. My friends love doing it....I think they are all on drugs though.
actually both DC and AC will both make you jump and throw you... it depends mostly on how you are positioned acc. to the shocking object.. AC WILL make you cramp... DC just does it worse... I have gotten quite a few shocks while at work.. and yes it can be quite dangerous, if you have gotten a severe shock, the chances of you having a heart attack in the first 24 hours is increased 40-60% many people have had limbs amputated because all the major veins have burnt away e.g. in your arm, but it may only show months later..
And yet another story to add to the pile... I was running phone cable in a building at work. After wiring up a jack, I had it in my hand and was talking to someone. Apparently, I had crossed both contacts...just as the phone rang. OUCH!!! It like triples the voltage running through the line. I was tingly for an hour. And just to add insult to injury....I had to wire up to a punchdown panel and ended up hitting two contacts...just as someone called on that line. DAMN!!
I don't think thats exactly true, I was shocked 4 times yesterday by 10v 4amp line, and also fell through a half inch thick table, Still alive, just had to superglue my leg together.
hmm, wouldnt that mean that shorting the 5v and 0v on a molex with your body, could quite easily kill you... thats doesnt sound realistic... also.. is it therefore far more dangerous to wear an antistaic wrist strap (that plug into the earth socket) than not.. speshly if its on the other hand than what your servicing with all this certainly sounds scary.. i remeber in electronic.. our teacher told us he used to rip apart disposable cameras.. take the caps out.. fill them.. then put em in peoples pockets.. apparently it felt like getting hit in the arm with a bat
it won't kill you. Neither will shorting 12v, and i know cause i've tried both. For it to be fatal. you'd need to cut the 5V line, and run one end to your body, and the other end from your body to a load; so you take in current.
