1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Planning All in one in CRT, planning.

Discussion in 'Modding' started by pyro1son, 12 Jan 2011.

  1. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
    In two weeks time, when my exams have finish, i will be starting the build of my all in one CRT PC.
    I have an old server cachebox from which all the internal component will come from, which include:
    -Mini-ITX (VIA C3)
    -HDD (IDE Grrr)
    -Power supply
    -RAM

    All the parts above are going to go inside of an old CRT monitor shell, and an old LCD screen shall be placed at the front. At the moment i am still planning the layout of the components and still sourcing a CRT and LCD monitor.

    Only two weeks till i can start the build! :D
    I look forward to reading your comments!
     
  2. saspro

    saspro IT monkey

    Joined:
    23 Apr 2009
    Posts:
    9,331
    Likes Received:
    239
    Just be careful ripping the CRT apart.

    Those things can store voltages for frackin ages & they're lethal.

    An old imac case makes a good starting point
     
  3. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
    any idea how to get rid of the voltages?

    i want to keep away from mac cases for this mod as i want to put linux on it :thumb:
     
  4. saspro

    saspro IT monkey

    Joined:
    23 Apr 2009
    Posts:
    9,331
    Likes Received:
    239
    Just make sure it's been turned off for ages and don't poke the caps with a screwdriver.
     
  5. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
    would it help if i grounded it with with a power cable without live connections?
     
  6. saspro

    saspro IT monkey

    Joined:
    23 Apr 2009
    Posts:
    9,331
    Likes Received:
    239
    Not really, it's not the case it's the caps etc on the power board & the back of the tube.

    Just wear rubber glovers and be careful and you should be fine.
     
  7. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
    ok cool what should i do with the insides?
     
  8. saspro

    saspro IT monkey

    Joined:
    23 Apr 2009
    Posts:
    9,331
    Likes Received:
    239
    Local dump?
     
  9. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
    oh ok didnt know if there was anywhere special i had to take that kind of thing
     
  10. Boscoe

    Boscoe Electronics extraordinaire.

    Joined:
    5 Jan 2010
    Posts:
    1,105
    Likes Received:
    50
    No! This is how you die! You could in theory NEVER TRY IT hold onto the caps all day and as long as you have insulation resistance to stop the 30KV or so jumping from you to something like earth you'd be fine!

    Again in theory but never do it, you could short the caps with a resistor to get rid of the charge but playing around with these voltages is nothing to be doing.

    By the way the screen itself is a capacitor (stores ~30KV especially on old stuff) you see the wire going to it? That's one of the terminals! Carbon is put on either side and the glass acts as a dielectric.

    Be careful and before you do anything think first! Knock the tube on the back with you elbow or something and you have 1/2" thick glass flying around due to the extreme vacuum inside!

    Good luck!
     
  11. bulldogjeff

    bulldogjeff The modding head is firmly back on.

    Joined:
    2 Mar 2010
    Posts:
    8,403
    Likes Received:
    634
    I don't know how true this is but I heard that leaving it off for 2 weeks is enough to discharge any stored power.
     
    mvagusta likes this.
  12. Boscoe

    Boscoe Electronics extraordinaire.

    Joined:
    5 Jan 2010
    Posts:
    1,105
    Likes Received:
    50
    It is still risky differences in designs and odd things happening makes me unsure when it comes to this sort of stuff!
     
  13. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
    Ok scary stuff! I shall be extreamly carefull! Thank you for the warning!

    Is it turned off or unplugged for ages for it to discharge, and become safe?

    I greatly appreciate the help your giving guys! :thumb:
     
    mvagusta likes this.
  14. mvagusta

    mvagusta Did a skid that went for two weeks.

    Joined:
    24 Dec 2006
    Posts:
    4,639
    Likes Received:
    523
    Feel free to discharge all of the capacitors with a screwdriver :thumb:

    No need to wear gloves, the handle of the screwdriver will insulate you, but you can put on some gloves if you are really worried.

    If there is still a big charge in any of the caps, you'll get some bright sparks and a pop/fizz noise from the spark. The current can easily be high enough to melt away a tiny bit of the solder where the screwdriver makes contact with the joint, and you can even create tiny pits/creaters on the screwdriver. This shorting is very similar to a arc welding, but on a tiny scale. You would want to squint as the sparks can be very bright, or wear some sunnies. If you look into the spark it's no biggie however, it's just like walking outside and having the sun catch your eye, or momentarily looking into a bright led torch.

    If you want to discharge each cap without the tiny arc weld show, you'd have to use a resistor, but I wouldn't bother.

    You can also check for residual charge by shorting out the connections on the little pcb, the one plugged into the pointy end of the tube.

    Remember that your monitor will be unplugged from the wall, it's only residual charge, so even if you were to short out a 240v cap with your finger tips, you'd just receive a short shock. It might sting a little, possibly make a tiny burn on your finger tip, and that's about it. Unless you have a pacemaker or something like that, then it might be a different story!

    The tube receives a very high voltage, as in 30 000v +, but it's a very low current. Car spark plugs typically receive ~50 000v, but you can get shocked from a spark plug lead, it will only sting a little. Voltage doesn't kill, it's the amps that does that.
     
    pyro1son likes this.
  15. Elledan

    Elledan New Member

    Joined:
    4 Feb 2009
    Posts:
    948
    Likes Received:
    34
    Screwdriver welding. Fun :D
     
    mvagusta likes this.
  16. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
    I have to say you guys do worry me at times.

    Im not going to be doing that, i think ill just leave it in the garden to discharge its self!
     
  17. confusis

    confusis Kiwi-modder

    Joined:
    5 Jan 2006
    Posts:
    2,406
    Likes Received:
    63
  18. mvagusta

    mvagusta Did a skid that went for two weeks.

    Joined:
    24 Dec 2006
    Posts:
    4,639
    Likes Received:
    523
    Well if you haven't ever played with electricity then it's understandable that you may be scared to do so, no probs :thumb:

    I don't know for sure if 2 weeks would be enough time for all the capacitors to fully discharge, but i'd say that any charge possibly left in them after 2 weeks, would be pretty small. Leave it for 3 weeks if you really wanna avoid any chance of seeing even a tiny spark I guess.

    Just to further clarify, the sort of sparks i'm talking about would be at the very most, as big as the sparkle emitted from a cake sparkler:

    [​IMG]

    So at the very most, you'd see that for a moment! It's like a birthday party, where you get to pull apart a tv!!!

    Oh and tv tubes aren't grenades btw! They hold a vacuum, so if you break them, a bit of air rushes into the tube, not out, so you don't get glass flying everywhere! If a crt tv was a lethal grenades of glass, none would ever have been sold to the public.

    edit: wow, alot of fear in that indestrucables link! One guy claims that a screw driver can't handle 10 000v :hehe: Silly people confusing high voltage with low current situations such as the tiny current crt tube charge, to huge power stations with large current flow! Have a look at the single wire coming out of the tube, the one that looks like a thin spark plug lead... rip it out of the tube, it's only a press fit, and check out how thin the metal is! That lead provides 30 000v+ depending on the model, but at a tiny current, which could only make a baby cry.
     
    Last edited: 13 Jan 2011
  19. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
  20. pyro1son

    pyro1son Linux User!

    Joined:
    18 Aug 2010
    Posts:
    509
    Likes Received:
    8
    Here's a little preview of what im going for.

    [​IMG]
    From this to...

    [​IMG]
    This!

    I had to do them in photo shop as i still havent mastered sketch up :confused:

    You probably cant see much change but i want it to look like a standard CRT there will be little things which may give it away.
     

Share This Page