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Modding Gutting CRTs

Discussion in 'Modding' started by Stwongbad, 19 Jun 2006.

  1. Stwongbad

    Stwongbad What's a Dremel?

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    ouch, that reminds me of the time I tried to take out some fuse thing in the switchbox in my house with a skrewdriver. . . I know how you feel
     
  2. Flyingsheep

    Flyingsheep What's a Dremel?

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    ouch, painful.
     
  3. Stwongbad

    Stwongbad What's a Dremel?

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    very painfull, I fell on my ass and was dazed for a second before I said "**** that" and went back on here to play counterstrike with a twichy right hand
     
  4. Snipes0990

    Snipes0990 What's a Dremel?

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    I am waay to lazy to read page two with comments about how dangerous messing with crt's can be, but they are all correct, so look at the fact that messing with crt's can be fatal and then ask yourself what you plan to do with the parts you remove, chances are you wont learn anything useful and any electrical modding projects probably will not call for the parts you will find in a crt, the only interesting mod i can think of with a crt is a jacobs ladder

    http://www.afrotechmods.com/reallycheap/Jacob/jacob.htm

    which can be extremely dangerous if you know nothing about them and i believe that the effect is more easily achieved using a neon sigh transformer
     
  5. mottl3y

    mottl3y What's a Dremel?

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    i had a shot pulling apart a CRT a few years ago. I got as far as using the discharge rod, but didnt hear any noise so called it quits. Thinking about it now, it is probably because i hadn't grounded the rod properly, how are you supposed to do it?

    and just to confirm: there's no caps that need to be worried about in lcds/plasmas? i know lcds use an inverter for the backlight.
     
  6. bubsterboo

    bubsterboo What's a Dremel?

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    Doesent anything that converts ac to dc need caps?
     
  7. scifi3018

    scifi3018 Minimodder

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    well, yes. Caps are needed to flatten out the sine wave that AC current looks like.
    But.. in mottl3y's defense, if his lcd/plasma has a power brick, then there need'nt be any caps in the lcd that i know of.
    And the inverters are dc-dc so there stil needs to be a converter to convert ac-dc
     
  8. ElThomsono

    ElThomsono Multimodder

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    The inverters in other screens are fine, the only reason that CRTs pose a threat is that the have some very large capacitors in them, storing extremely high voltages. Capacitors in other devices are usually tiny by comparison, and discharge quickly.
     
  9. bender386

    bender386 What's a Dremel?

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  10. Stwongbad

    Stwongbad What's a Dremel?

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    Ahem...Who said my crt doesnt have x-rays?
     
  11. gideon

    gideon What's a Dremel?

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    What i was thinking those caps are thousends of volts, 20ma will kill you, lets say 15000 volt (flyback transformer) at 20ma is 300watt, correct me if im wrong (well probably) but i dont think a tv has that much of power stored.

    remeber:
    volts hurts
    current kills

    if i'm wrong please correct me.
     
  12. Spoon

    Spoon What's a Dremel?

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    Yup, TV's produce x-rays when they are ON. I think they're emitted when the electrons that are accelerated in cathode ray slow down on encountering metal in the tube or the phosphors on the screen. Each electron's kinetic energy is converted in to high energy electromagnetic radiation; X-rays. Just like a small version of all the particle accelerates used to search for new sub-atomic particles.

    Luckily some of the energy is also converted (via the phosphors) into lower energy EM radiation; visible light so we can see a picture.

    Possibly you didn't here any noise cause they'd discharged already. How long had the CRT been off before you tried?

    Although it is true some caps hold a deadly voltage for years, some even inside various appliances. Caps in a circuit usually will have a connection to ground at some fairly high resitance, just by nature of how they are used in the circuit, so will discharge over time. The problem comes for test and repair people who turn the CRT off and test straight away.
     
  13. Snipes0990

    Snipes0990 What's a Dremel?

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    you can conver ac to dc using a diode bridge rectifier
     
  14. Snipes0990

    Snipes0990 What's a Dremel?

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    50mA causes fibrilation (death) in average males less so for women and this number can range depending on the amount of fat (more conductivity) muscle (less conductive)

    a tv/crt definatley has enough miliamp in the capacitors to kill you b/c when you touch the terminals that trace back to the caps you are creating a dead short and will be discharging the capacitors into you
     
  15. TimEG

    TimEG What's a Dremel?

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    Is fat more conductive that muscle??? That sounds counter-intuative? I foun d this on the net: "Fat tissue is anhydrous and resists an electrical signal, while muscle tissue is relatively hydrated and conducts an electrical signal."
     
  16. airchie

    airchie What's a Dremel?

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    Cool, I'm pretty chubby so even if I did touch the wrong part of the insides of the telly, I think I'd still be safe... :D
     
  17. woof82

    woof82 What's a Dremel?

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    Wtf. Surely to discharge a cap you just need to short them. Where did all this "grounded rod" rubbish come from?!

    You can probably short them with a screwdriver. I've seen one the size of a mini coke can (like the cans on an airplane) discharged with a screwdriver. Not that exciting tbh.

    Obviously it's dangerous, but some of you guys have said things that are just plain silly.
     
  18. smoguzbenjamin

    smoguzbenjamin "That guy"

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    Now it seems to me like everyone's dead scared of caps. Let's get it straight.

    Big caps - dodgey
    Small caps - safe enough
    High voltage - ouch
    High current - dead modder

    It's as simple as that.

    And by the way, if you only use a diode bridge rectifier to rectify AC into DC you get a funky waveform which looks like a sinewave with all the negative peaks flipped positive. What the capacitors do is smooth that out to create a (relative) DC power source.
     
  19. woof82

    woof82 What's a Dremel?

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    ^ Someone said something intelligent.
     
  20. crazydeep74

    crazydeep74 What's a Dremel?

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    Ive read on how to discharge them, honestly I wouldnt even try. I read there is a very loud pop, and im bound even if I expect it, too jump and accidently hit osmething I shouldnt hit. I have a question though. I want to take my 3 CRT's apart to paint them. Will I have much too worry about when I open it?
     

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