4 ms·

If you like playing with old hardware, be aware that old CRTs have a gotcha that can getcha: they hold a charge that can shock you across the room, and they can

If you like playing with old hardware, be aware that old CRTs have a gotcha that can getcha: they hold a charge that can shock you across the room, and they can hold that charge for weeks or more. Google how to discharge it before poking around in a CRT.

asciii 9mo ago
My family bought our first one and we used it keep it on a carpet floor - boy was that an electrifying experience
RedShift1 9mo ago
Not just shock you across the room, but shock straight into your next life.
- actionfromafar 9mo ago
  So we are all in post-tube life?
Scubabear68 9mo ago
When I was about 12 I got an old TV in my room which I of course decided to take apart to figure out how it worked. I was VERY smart and of course unplugged the TV before doing anything. My flat head screwdriver brushed against the wrong terminal in the back, I was literally thrown across the room several feet, and my flat head screw driver was no longer usable as the tip had deformed and slightly melted. I later found an electronics book that had a footnote mentioning grounding out the tube before going near it…
- preisschild 9mo ago
  Yeah the tube is essentially a large capacitor :P I also learned electronics by shocking myself often
  - nojvek 9mo ago
    You either learn by shocking yourself, or die trying. The survival selection is real in electronics.
  - fennecbutt 9mo ago
    It's not the tube (which is just a chamber for an electron gun. It's the high voltage capacitors used to hold charge for the supply driving the electron gun.
    - userbinator 9mo ago
      It's the tube itself which forms the capacitor. I'm not aware of any sets that used a separate capacitor across the final anode voltage.
- nextaccountic 9mo ago
  How does an electric shock throws someone across the room? What's the mechanism for this push? I know a shock can paralyze (by contracting the muscles) and it can burn (by joule effect) but never seen one push
  - userbinator 9mo ago
    "by contracting the muscles"
  - LeoPanthera 9mo ago
    Typically it forces your leg muscles to contract as the current flows to ground and you literally kick yourself into the air. Exact same thing happened to me as a child. I do not remember the event, but I do remember waking up on the other side of the room.
  - db48x 9mo ago
    AC current paralyzes by alternately contracting and relaxing your muscles, 60 times per second. This tends to lock you in place because the electricity is a higher voltage than your nerves and overrides any command you send every 60th of a second. It could take you several minutes to die, and you will be suffering in pain and terror the whole time as you are unable to let go… DC current jolts you “across the room“ by contracting your muscles all at once. Of course the exact effect depends on your posture; sometimes it just makes you stand upright or pull your arms in. This tends to disconnect you from the source of the electricity, limiting the damage. Note that if you cannot actually jump all the way across the room then the jolt probably can’t knock you all the way across the room either. If you fall over your head could end up pretty far away from where it started, though, and if you lose consciousness even for a little while then that can affect your perception too. It could certainly throw the screwdriver all the way across the room. If you pay attention to the special effects that show up in movies and television you’ll soon realize that they simulate shocks by putting the actor in a harness and then pulling on it suddenly. This sudden movement away from the source of the “shock” stops looking very convincing when you notice that the movement starts at their torso rather than in their legs and arms.
    - 9mo ago
addandsubtract 9mo ago
Same goes for your microwave.
macintux 9mo ago
I have a vague recollection that my little cousin was nearly ended when he managed to destabilize the stand that a CRT was sitting on, and it fell just behind him, but I may be entirely hallucinating that memory. Regardless, there are multiple ways old CRTs can cause great harm.

asciii 9mo ago

My family bought our first one and we used it keep it on a carpet floor - boy was that an electrifying experience

RedShift1 9mo ago

Not just shock you across the room, but shock straight into your next life.

actionfromafar 9mo ago
So we are all in post-tube life?

Scubabear68 9mo ago

When I was about 12 I got an old TV in my room which I of course decided to take apart to figure out how it worked. I was VERY smart and of course unplugged the TV before doing anything. My flat head screwdriver brushed against the wrong terminal in the back, I was literally thrown across the room several feet, and my flat head screw driver was no longer usable as the tip had deformed and slightly melted. I later found an electronics book that had a footnote mentioning grounding out the tube before going near it…

preisschild 9mo ago
Yeah the tube is essentially a large capacitor :P I also learned electronics by shocking myself often
- nojvek 9mo ago
  You either learn by shocking yourself, or die trying. The survival selection is real in electronics.
- fennecbutt 9mo ago
  It's not the tube (which is just a chamber for an electron gun. It's the high voltage capacitors used to hold charge for the supply driving the electron gun.
  - userbinator 9mo ago
    It's the tube itself which forms the capacitor. I'm not aware of any sets that used a separate capacitor across the final anode voltage.
nextaccountic 9mo ago
How does an electric shock throws someone across the room? What's the mechanism for this push? I know a shock can paralyze (by contracting the muscles) and it can burn (by joule effect) but never seen one push
- userbinator 9mo ago
  "by contracting the muscles"
- LeoPanthera 9mo ago
  Typically it forces your leg muscles to contract as the current flows to ground and you literally kick yourself into the air. Exact same thing happened to me as a child. I do not remember the event, but I do remember waking up on the other side of the room.
- db48x 9mo ago
  AC current paralyzes by alternately contracting and relaxing your muscles, 60 times per second. This tends to lock you in place because the electricity is a higher voltage than your nerves and overrides any command you send every 60th of a second. It could take you several minutes to die, and you will be suffering in pain and terror the whole time as you are unable to let go… DC current jolts you “across the room“ by contracting your muscles all at once. Of course the exact effect depends on your posture; sometimes it just makes you stand upright or pull your arms in. This tends to disconnect you from the source of the electricity, limiting the damage. Note that if you cannot actually jump all the way across the room then the jolt probably can’t knock you all the way across the room either. If you fall over your head could end up pretty far away from where it started, though, and if you lose consciousness even for a little while then that can affect your perception too. It could certainly throw the screwdriver all the way across the room. If you pay attention to the special effects that show up in movies and television you’ll soon realize that they simulate shocks by putting the actor in a harness and then pulling on it suddenly. This sudden movement away from the source of the “shock” stops looking very convincing when you notice that the movement starts at their torso rather than in their legs and arms.
  - 9mo ago

addandsubtract 9mo ago

Same goes for your microwave.

macintux 9mo ago

I have a vague recollection that my little cousin was nearly ended when he managed to destabilize the stand that a CRT was sitting on, and it fell just behind him, but I may be entirely hallucinating that memory. Regardless, there are multiple ways old CRTs can cause great harm.