Shocking TV

June 2, 2005 11:29 AM

Has anyone shocked while tampering with their television really been thrown across the room into/through a wall?
posted by angry modem to Society & Culture (26 answers total)

Best answer: i've been thrown across a room and hit the opposite wall by a mains shock - the button was missing on a hand drier in a pub bathroom, so i stuck my finger inside to switch it on.
obviously, it's not the electricity doing the throwing, but the muscle spasm it provokes. and the wall wasn't far away.
posted by andrew cooke at 11:33 AM on June 2, 2005

Best answer: oops. somehow posted without this - i assume a tv shock could be much worse. they have much higher voltages and big enough capacitance to kill (unlike mains, which normally doesn't, at least in my experience).
posted by andrew cooke at 11:36 AM on June 2, 2005

Best answer: I've found myself on the other side of the room once after working on a ceiling fan/light without turning off the breaker first. I'm with andrew cooke above that the TV is probably enough to do you in.
posted by NotMyselfRightNow at 11:40 AM on June 2, 2005

Response by poster: Hot, thanks.
posted by angry modem at 11:43 AM on June 2, 2005

I think one of two things would happen, your muscles would involuntarily contract and you would hold on tightly to the tv, or you would be thrown a bit by the spark (there is a huge... HUGE charge in some television parts). Sounds like a job for mythbusters.
posted by drezdn at 11:48 AM on June 2, 2005

My mom was crouched over, sticking a fork into the underside of the oven trying to get the pilot to light and the next thing I knew she was flat on her back on the other side of the kitchen. And a friend reportedly flew across the room after trying to fix a broken television, but he is prone to exaggeration and no one was there to witness it.
posted by dual_action at 11:48 AM on June 2, 2005

I've been zapped by 2000 volts (but very low amps) in a piece of USAF communication gear - no big deal; and several times by 120 volts AC which wasn't such a big deal under the circumstances but could have been, depending.

However, once when working at a drycleaners & moving clothes from the washer to the "extractor" (i.e., the separate spin cyle machine) I was standing in water & when I hit the start button (which had a short) it indeed blew me across the room - scared the living shit out of me. It was a 240-volt circuit. It's those pesky little amps that get you - anything 60 milliamps pr over can fry you under the right conditions.
posted by Pressed Rat at 11:52 AM on June 2, 2005

It's nontrivial to be killed by a shock from a broken CRT. Those things are like giant capacitors.
posted by mr_roboto at 11:54 AM on June 2, 2005

I would say that being killed by anything is non-trivial.
posted by adamrice at 11:58 AM on June 2, 2005

It's the muscle spasm that throws you across the room (and possibly breaks bones, tears ligaments, etc.). The actual energy of the spark wouldn't do that without blowing everything else across the room too — it's not directed at you.
posted by hattifattener at 12:02 PM on June 2, 2005

I used to work for an Apple Specialist doing repair work. Once while taking apart an old Mac Plus, I wasn't careful enough and touched the wire leading to the anode cap -- a.k.a the mean red wire. It didn't kill me, obviously, but it shot my ass out of my chair pretty hard.

I believe the later compacts (SE and on) had a resistor which bled the excess energy and prevented against this; the Plus may even have had one, but it wasn't functional.

Come to think of it, I also electrocuted myself installing a fluorescent bulb into a broken fixture (the contacts were exposed) -- I should have died at 16!
posted by symphonik at 12:13 PM on June 2, 2005

(side note: you are supposed to discharge those CRTs with a special tool; I had intended to do so but I contacted the wire before that point. :P)
posted by symphonik at 12:14 PM on June 2, 2005

I would say that being killed by anything is non-trivial.

Heh. The thing is I misposted: I meant to say it was "trivial" to be killed by a discharging CRT. Those things pack a wallop.
posted by mr_roboto at 12:22 PM on June 2, 2005

Hot, thanks.
posted by angry modem at 11:43 AM PST on June 2 [!]

Well put.
posted by NotMyselfRightNow at 12:25 PM on June 2, 2005

And what's with the "christmas" tag?
posted by NotMyselfRightNow at 12:26 PM on June 2, 2005

Yeah, what is with the Christmas tag?! (Man, that made me laugh aloud. WTF.)

When my great aunt was a child, she screwed in a brass bedpost ball into a lamp and was thrown across the room.

What's scary is that 1.5 volts run through your heart will stop it...
posted by Specklet at 12:34 PM on June 2, 2005

The "wallop" in capacitors, as used in televisions, comes from the fact that they store extremely high voltages. When a television (or for that matter, many electric motors) starts up, the capacitor provides the big kick that gets the whole thing rolling by means of a large discharge of high voltage (thousands of volts). This voltage is present even when the TV is unplugged. Think of them as a great big electrical accumulators.
posted by Doohickie at 12:39 PM on June 2, 2005

Only in the movies do you go through the wall unless you are really really clumsy.
If you start poking around in the back of the TV with a screwdriver it is most likely you will be blinded by flying molten metal from causing a high voltage short circuit when you touch the wrong spot while playing Mr. Repairman.
Using your bare fingers is also a good way to check out how well stocked your medicine cabinet is.
Touch the wrong place in the TV chassis and you will experience the high voltage "Jerk Reflex". Your arm/hand will come flying out of the TV near the speed of light probably catching some part of your appendage on a sharp corner of the TV during the high speed exit.
Go through the wall? no
Banging your head on the wall for being so stupid? yes
posted by Shalerman at 1:25 PM on June 2, 2005

I used to work on high-voltage electron spectrometers, essentially research-grade TV guns. Everyone who had done maintenance on them had touched the high voltage (500 to 12000 V, low amp DC) exactly once. My experience merely melted through the haft of the screwdriver I was holding and gave me a mild buzz. A fellow student, however, was unlucky enough to be holding onto the metal cage around the spectrometer with his other hand, thus causing the discharge to cross his chest, and had moderate heart palpitations as a result.

The really dangerous events, like that of my fellow student, were those where the current caused muscles to freeze, hands to clench, so that one couldn't let go. Alex had no motor control in either hand when the discharge hit --- he was saved by the power supply blowing a fuse. He figured he wouldn't have been able to let go on his own. We were all kind of freaked-out by that, but just replaced the fuse and kept working on the instrument.
posted by bonehead at 1:25 PM on June 2, 2005

The rule I used when working on terminals and monitors was simple. I worked on the floor, so I couldn't fall as far. The one time I touched the wrong wire while adjusting things, I was slammed onto the floor, but that was it.

Why did I learn this trick? I saw someone touch the output of the flyback transformer. He didn't go through the wall, but he was thrown into it by the massive all-body muscle spasm induced by the very high voltage output of the flyback.
posted by eriko at 1:51 PM on June 2, 2005

Maybe the "Christmas" tag is because you light up like a Christmas tree?
posted by Mo Nickels at 2:04 PM on June 2, 2005

I'm really surprised no-one has yet commented that an A.C. current will do the throwing and D.C. will have you stuck to whatever until the current is switched off. Basically the A.C. is alternating so you get the shocks and muscle spasms and when the current switches off that's when you get thrown away! With a D.C. it is a direct current and doesn't give you that time to release. I'm sure that I can be backed up by a bit of googling but it's late.....
posted by floanna at 3:31 PM on June 2, 2005

Both my father and grandfather were TV repairmen, and I only by proxy. Both were deathly afraid of the flyback and surrounding caps. Don't fuck with CRTs if you don't know what you're doing.
posted by Civil_Disobedient at 3:56 PM on June 2, 2005

the trick to doing high voltage repairs: keep one hand in your pocket. The voltage can't cross your heart.
posted by hortense at 10:54 PM on June 2, 2005

On the off chance that people still catch this - Bonehead's comment about the 'really dangerous events' reminded me of a run in I had when I was a kid.
Crappy drill, shorted, and I remember shaking on the ground for 10-30 secs and I could not let go of the drill. Felt like both my arms were paralyzed. Finally my friend's dad had enough sense to unplug the thing and I was rather dazed for a bit afterward.
But just wondering for when I have kids, is this the kind of thing you should take someone to a hospital for? Or a 'rub some dirt on it, you'll be fine' kind of injury?
posted by efalk at 3:14 AM on June 3, 2005

I had a college prof who was messing around inside a CRT monitor once and ended up with a bad electrical burn on his finger and wound up on the floor.

Also, my mom worked for GTE (pre-Verizon) and was up on a ladder in the GTE building, working on some wires above her head, and her wrist hit the wires on one side, got knocked into the wires on the other, and back and forth a few times before she could yank her arm down.

efalk - I'd take them to the hospital, just to be safe, especially if they're dazed. Ya never want to mess around with something like that, especially if the kid can't tell you exactly what he/she feels and where.
posted by IndigoRain at 8:37 AM on June 3, 2005