your 100volt plus moment
I've had some lately and was wondering if others lived to tell.
My first one was 400-600Volts dc.
Opened a Photo camera, aware of the high voltage i put it at save distance. let my screwdriver fall, wanted to pick it up, got unbalanced and grabbed right in the guts of the cam. I was affected for two weeks.
the second was last week. I bought a small flipswitch (with metal lever) for AC/mains switching. soldered the bastard in and tried switching the switch. BANG and i was laying on my bed a good 2 meters away. Opended the switsch and discoverded they forgot an insulating piece of rubber.
(don't ever open such a switch! You never want to tuch one again if you see how crappy they are constructed)
Allthough rated 250 Volts, Use insulated switches in the future!
I had a few near misses with measuring cables, accidentally plugged out of the measuring devices, but not out of the amp, leaving banana plugs loaded with 800volts in the open...
Bas
I've had some lately and was wondering if others lived to tell.
My first one was 400-600Volts dc.
Opened a Photo camera, aware of the high voltage i put it at save distance. let my screwdriver fall, wanted to pick it up, got unbalanced and grabbed right in the guts of the cam. I was affected for two weeks.
the second was last week. I bought a small flipswitch (with metal lever) for AC/mains switching. soldered the bastard in and tried switching the switch. BANG and i was laying on my bed a good 2 meters away. Opended the switsch and discoverded they forgot an insulating piece of rubber.
(don't ever open such a switch! You never want to tuch one again if you see how crappy they are constructed)
Allthough rated 250 Volts, Use insulated switches in the future!
I had a few near misses with measuring cables, accidentally plugged out of the measuring devices, but not out of the amp, leaving banana plugs loaded with 800volts in the open...
Bas
So you had a mains switch with a metal toggle? Good commercial practice is to have some means of earthing such a switch (which would have prevented your accident). I'd never heard of such a precaution genuinely being needed before but use it because I'm a "belt and braces" sort of fellow when it comes to electrical safety.
hahaha too many too mention, but 2 occasions I do remember ...
One I was still pretty young and had one of these bedlamps that clamp to the headboard... anyway, sometime after I went to bed a light blew somewher in the house, and for some reason, my parents decided to come and talke the bulb from my lamp... so somewhere in the night I half woke up, tried to switch on the light, but it stayed dark... so I started feeling around where the lamp is, only to manage to stick my fingers dead centre into prongs of the now empty, and switched on lightsocket.... made a loud bang in my head and I couldn't hear anything except a loud ringing for an hour or so...
the other time, a had too many powercables needing plugs by my workstation, so I ended up with one open plug I used to just wire directly (don't do this at home kids) anyhow, this jobby was standing on the floor and so one afternoon while soldering I managed to step right onto the open plug, barefoot!
Ended up laying behind the chair I was sitting it, while the chair didn't even seem to move.
P.S. havent had one of these blonde moments in 12 years or so, some of us just won't take warnings at face value...
250V/15A is fun!
One I was still pretty young and had one of these bedlamps that clamp to the headboard... anyway, sometime after I went to bed a light blew somewher in the house, and for some reason, my parents decided to come and talke the bulb from my lamp... so somewhere in the night I half woke up, tried to switch on the light, but it stayed dark... so I started feeling around where the lamp is, only to manage to stick my fingers dead centre into prongs of the now empty, and switched on lightsocket.... made a loud bang in my head and I couldn't hear anything except a loud ringing for an hour or so...
the other time, a had too many powercables needing plugs by my workstation, so I ended up with one open plug I used to just wire directly (don't do this at home kids) anyhow, this jobby was standing on the floor and so one afternoon while soldering I managed to step right onto the open plug, barefoot!
Ended up laying behind the chair I was sitting it, while the chair didn't even seem to move.
P.S. havent had one of these blonde moments in 12 years or so, some of us just won't take warnings at face value...
250V/15A is fun!
Worked on a pair of Marantz 9's some 10 years ago, and one of the first things I discovered was that the power switches in both had developed a dead short to the bat when in the "on" position, connecting one side of the power line directly and inadvertantly to the chassis. These amplifiers had unpolarized plugs on them, and one of the things the owner complained about was getting an electric shock when turning them on and off.. LOL Fortunately no one was injured as both amplifiers were plugged in the same way to neutral.
My own story was as a teenager getting two fingers across the 240V mains in Brussels whilst repairing a Revox G36.. The involuntary contraction of my arm muscles while I watched in fascinated horror as my arm swung towards my face and hit me **hard** in my forehead has left an indelible memory. While very quick I even had enough time to think of the time lapse photography in the opening sequences of the "Six Million Dollar Man" and the stupid noises that accompanied it. To this day when I think about that incident I hear those noises..
I have been very careful since that time and have not had any encounters with high voltages which is a good thing since many of my designs employ voltages of up to 700V. One such 572-3 based amplifier operated on 1100Vdc, and that was an amplifier I truly feared...
My own story was as a teenager getting two fingers across the 240V mains in Brussels whilst repairing a Revox G36.. The involuntary contraction of my arm muscles while I watched in fascinated horror as my arm swung towards my face and hit me **hard** in my forehead has left an indelible memory. While very quick I even had enough time to think of the time lapse photography in the opening sequences of the "Six Million Dollar Man" and the stupid noises that accompanied it. To this day when I think about that incident I hear those noises..
I have been very careful since that time and have not had any encounters with high voltages which is a good thing since many of my designs employ voltages of up to 700V. One such 572-3 based amplifier operated on 1100Vdc, and that was an amplifier I truly feared...
450 VDC zap
At age 11, I was building a PS for an old WWII shortwave radio. Got across 450 vdc. I can report 45 years later never getting zapped since.
I was a bit unusual at age 11 as I like shortwave radios & taught myself the basics from reading a ARRL (Ham radio) Handbook cover to cover many times. At age of 16 everyone else was experimenting in human biology except me still experimenting in the electronics lab.
At age 11, I was building a PS for an old WWII shortwave radio. Got across 450 vdc. I can report 45 years later never getting zapped since.
I was a bit unusual at age 11 as I like shortwave radios & taught myself the basics from reading a ARRL (Ham radio) Handbook cover to cover many times. At age of 16 everyone else was experimenting in human biology except me still experimenting in the electronics lab.
A friend of mine had an 8Kv high capacity encounter. He was in coma for two weeks. The 3cm thick wire he was working on was molten through the concrete. The spanner he was working with was never found....
He still has concentration problems (20 years later) and reduced ability to sense things..
He still has concentration problems (20 years later) and reduced ability to sense things..
One of the guys in the ham radio club in my high school (decades ago) thoiught it would be funny to rig up the code practice key to turn on a 1,500V power supply hooked to the metal chair frame.
On a nice warm day with no air conditioning, I went in to practice my code. I jumped over the back of the chair and hit the wall a yard or so behind me, probably still a couple feet in the air. Fortunately he'd thought to put a current limiting resistor in the circuit, but it sure didn't feel like it had been limited much.
I should have pounded that kid to a pulp - but I am sure someone has since.
On a nice warm day with no air conditioning, I went in to practice my code. I jumped over the back of the chair and hit the wall a yard or so behind me, probably still a couple feet in the air. Fortunately he'd thought to put a current limiting resistor in the circuit, but it sure didn't feel like it had been limited much.
I should have pounded that kid to a pulp - but I am sure someone has since.
Once working on the guts of a computer monitor I managed to find the horizontal deflection waveform terminal lug on the yoke. Knocked me a second or so into the future. IOW, I seemed to have skipped a second of time. Horizontal deflection circuits develop kilovolt level spikes in normal operation.
Yes, horizontal scan is very nasty. I caught one of those when I had my arms in the back of a monitor and was adjusting the magnets just behind the scan coils whilst watching the display at the front. I didn't suffer quite the effects you did, but I still reported it as an accident and filled out the accident report book.
Lest anyone here is thinking of attempting bravura regarding electricity, could I please remind everyone that it's nasty stuff and "20 mils kills." Yes, 20mA flowing through your body is enough to kill you.
Lest anyone here is thinking of attempting bravura regarding electricity, could I please remind everyone that it's nasty stuff and "20 mils kills." Yes, 20mA flowing through your body is enough to kill you.
The thing that counts is mils through the heart (actually, the sinus, which is located in your heart.)
4mA through your heart can allready kill...
Just remembered. When i was 7 or 8, we got an amp from my dad to disect.
I removed the PS with Power cable attached.
i was looking at it in awe when my little brother saw an unplugged power plug...
do the math
Bas
4mA through your heart can allready kill...
Just remembered. When i was 7 or 8, we got an amp from my dad to disect.
I removed the PS with Power cable attached.
i was looking at it in awe when my little brother saw an unplugged power plug...
do the math
Bas
EC8010 said:
A question just popped up in my mind.
When I measure the resistance between my hands. like 1.8meter of body from test lead to test lead, I get 2MOhm with damp hands, and an unsteady but about twice as hig resistance with dry hands.
As I have understood this, it is the current that kills?
Now to get 20 mA I would need to be zapped by 40kV.
How can it be that people die from 400VAC then? It is just 0.0002A.
Magura
Skin resistance is a very variable thing. Further, it's not a linear resistor - the value changes with applied voltage.
Many years ago I wanted to soak test a 50V 2A power supply. We didn't have any 100W resistors at work, so (thinking I was clever) I mixed up a solution of salt water and popped a couple of electrodes in, connected an ammeter in series and adjusted the electrodes until 2A was drawn. The resistance measured by a meter was completely different. I believe that the body is effectively a large bag of salty water...
Many years ago I wanted to soak test a 50V 2A power supply. We didn't have any 100W resistors at work, so (thinking I was clever) I mixed up a solution of salt water and popped a couple of electrodes in, connected an ammeter in series and adjusted the electrodes until 2A was drawn. The resistance measured by a meter was completely different. I believe that the body is effectively a large bag of salty water...
my first contact with mains, i had just dissected a pairof computer speakers (i was around 11) without realising i left it plugged in. i ripped the cord out the back and my hand touched the bare wires. i dont remember much about what happened to me, it wasnt a big deal (surprisingly) i just had a big shock and i remember a burn on the dead skin of my thumb. maybe that dead skin saved me from something much worse? i dunno.
second encounter, we had a light switch that was upside down forever and one day it just bugged me for the last time. unscrewed the panel and went to twist it around, and for some reason the outer metal case of the switch was live. got a nasty buzz there but nothing major happened that time either. i guess im lucky
ive also hit the flash cap in cameras many, many times. nice shock but as far as i know its not anything majorly fatal
second encounter, we had a light switch that was upside down forever and one day it just bugged me for the last time. unscrewed the panel and went to twist it around, and for some reason the outer metal case of the switch was live. got a nasty buzz there but nothing major happened that time either. i guess im lucky
ive also hit the flash cap in cameras many, many times. nice shock but as far as i know its not anything majorly fatal
I have to admit being shocked several times over the years. The most lingering were the two times I touched the focus control behind the panel of a pair of 'scopes. I just went to move the darn things while working on them (old tube ones), separated by a few years. Got nailed by 120 VAC and 300 ~ 450 VDC a couple times. I love it when people plug stuff in while you are working on it. They actually thought it was funny.
Then there was my lab partner who plugged in a transformer as I hooked it up for an experiment at Ryerson. We were going to use an oscillator as an exciter. He just saw the AC plug and mindlessly plugged it in, I didn't see him do it. It was a step up too!
-Chris
Then there was my lab partner who plugged in a transformer as I hooked it up for an experiment at Ryerson. We were going to use an oscillator as an exciter. He just saw the AC plug and mindlessly plugged it in, I didn't see him do it. It was a step up too!
-Chris
Biggest Nutter I ever met
I worked in a Medical Eelctronics Service Department for a while.
We had a tech who used to light his cigarettes by using a screw driver to draw an arc of the EHT Supply of a Color Television Set (25 to 30 thousand volts). He would lean forward until the cig was in the arc and then draw hard. He said he never had any problem unless the cigarette was damp.
My own opinion was that there was not much in his head that a shock would damage. Perhaps it was just that vacuum is such a good insulator that there was no current path through his head.
My worst experience from that time was a test probe slip which connected me across the main storage capacitors of a Cardiac Defibrillator (before the vacuum relay and pulse shaping components). Blew me off my chair and spread eagled me against a wall 2 metres away. I spent the rest of that day having a snooze in Casualty Department hooked up to a heart monitor.
I ALWAYS applied the correct safety procedures when working an 700W Siemens Surgical Diathermy units however. Those 2000V 800mA supplies to the Output Transmitter Tubes had me properly respectful without any need to see if I would survive contact with it.
In 33 years in the Electronics Industry I have had quite a few minor shocks usually caused by complacancy, working on equipment which I figured did'nt have enough wick to be dangerous. Just that one serious incident though. You can NEVER be too careful. The few occassions when I was not careful enough were significant learning experiences which I have been LUCKY enough to survive.
Please no testosterone junky rubbish trying to one-up these experiences here. If you don't treat electrical safety VERY seriously may I suggest you need a new/different hobby.
Cheers,
Ian
I worked in a Medical Eelctronics Service Department for a while.
We had a tech who used to light his cigarettes by using a screw driver to draw an arc of the EHT Supply of a Color Television Set (25 to 30 thousand volts). He would lean forward until the cig was in the arc and then draw hard. He said he never had any problem unless the cigarette was damp.
My own opinion was that there was not much in his head that a shock would damage. Perhaps it was just that vacuum is such a good insulator that there was no current path through his head.
My worst experience from that time was a test probe slip which connected me across the main storage capacitors of a Cardiac Defibrillator (before the vacuum relay and pulse shaping components). Blew me off my chair and spread eagled me against a wall 2 metres away. I spent the rest of that day having a snooze in Casualty Department hooked up to a heart monitor.
I ALWAYS applied the correct safety procedures when working an 700W Siemens Surgical Diathermy units however. Those 2000V 800mA supplies to the Output Transmitter Tubes had me properly respectful without any need to see if I would survive contact with it.
In 33 years in the Electronics Industry I have had quite a few minor shocks usually caused by complacancy, working on equipment which I figured did'nt have enough wick to be dangerous. Just that one serious incident though. You can NEVER be too careful. The few occassions when I was not careful enough were significant learning experiences which I have been LUCKY enough to survive.
Please no testosterone junky rubbish trying to one-up these experiences here. If you don't treat electrical safety VERY seriously may I suggest you need a new/different hobby.
Cheers,
Ian
When I was a kid, I was sledding with a friend in the cow pasture behind our neighborhood, and I grabbed an elecric fence with both hands. All I remember is being unable to let go, shaking a bunch, and finally being disconnected from the fence by gravity -- that is, I fell down. I don't know what the voltage was, but I gather these things can get into the thousands. I also don't recall any ill effects, though it was not a pleasant experience.
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