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Thread: Homebrew HV & other 'junk'

  1. #21
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    HA!! Yeah the idiot's me, and Adam-you nailed it right on the head! Long day, toddy time -but I finally remembered my "most useless device" so had to put it up right then b4 I forgot. Dr- I think your rabbit-hutch-argon is great and a Jacobs ladder is waycool too. No 1950s sci-fi movie would be complete w/o one

  2. #22
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    Quote Originally Posted by steve-o View Post
    I finally found my most useless device...
    http://www.youtube.com/watch?v=4iUASNmjcgo


    Hey Steve,
    Cool project. I have always wanted to build one of these. I couldn't find any schematics on instructions on the net. It's basically an inductor, a rectifier, some caps and two carbon rods right? Any info you can supply would be most appreciated.
    Thanks!
    Adam

  3. #23
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    Thanx Adam
    I'll put up a schematic.

  4. #24
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    More junk - the desktop Jacob's ladder.
    Think I could get light out of a pair of carbon rods with it though.
    http://www.die4laser.com/D4Sparks/Jacobs_ladder.mpg

  5. #25
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    That's COOL.................................................. ..

  6. #26
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    Cool

    Wow! The arc really moves fast on that one! What affects the speed? Can you slow it down or speed it up, or is it a fuction of the design? (Or the spacing of the rods?)

    Very cool though!

    Adam

  7. #27
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    Nice, a flyback transformer? Useful thingers, methinks. Buffo, I think the rod angle might have some effect but it's mostly heat, the arc rises with its own heat till it breaks. Changes in conductivity can anchor an arc for a while, as that clip shows. My first attempt had that problem so bad the arc wouldn't rise. Clean polished metal with no bumps in it helps, and bulk to conduct heat away especially if your source has a high current. I guess choice of metal can affect arc colour, but I haven't made enough to know.

  8. #28
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    Erm - I didn't look too closely into the physics.
    I had just built a ZVS driver for the flyback transformer and once you have tested it by drawing your first arc there is only one thing left to do ;-)
    The speed is likely the result of the power going into the arc - the better part of 100W at its highest point & also the waveform being high frequency. (Actually high frequency pulsed DC - you note the arc rise is asymmetric between the two electrodes - one favors climbing)

  9. #29
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    Quote Originally Posted by uk-laser View Post
    (Actually high frequency pulsed DC - you note the arc rise is asymmetric between the two electrodes - one favors climbing)
    That's interesting. Any chance you can rig one to reverse polarity to see if the arc swaps to favour the other end? Power in means heat, the rise is based on that I think, so as current is equal at all points in the arc unless the density/volume is different at one end, this apparent polarity is weird. It implies chemical reaction, so you might need to renew metal surfaces to retest each time by a bit of Brasso or such.

  10. #30
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    Hey Steve,
    Cool project. I have always wanted to build one of these. I couldn't find any schematics on instructions on the net. It's basically an inductor, a rectifier, some caps and two carbon rods right? Any info you can supply would be most appreciated.
    Thanks!
    Adam
    Here ya' go Adam,
    The gap is (2) 1/4-20 grade 8 bolts spring loaded to contact then release.
    They glow red hot after 30 sec or so and they do disintegrate and shorten after used for a while.
    Now if I could just figure out how to make this thing lase...

    <edit>
    To be on the safe side you should really go with a 40 Ohm 600 Watt resistor instead of 200W. I just did a re-calculation.
    I used what I had laying around and i take chances (+ I dont leave it on very long, and it smokes too and I dont know what's in that smoke.) I may add that to the pic. Also make the caps 1000uF instead of 330 (another re-calc)
    Also, should probably wear safety glasses (just thought of that.) Hind-sight is 20/20..
    Attached Thumbnails Attached Thumbnails arcer schematic.JPG  

    Last edited by steve-o; 08-21-2007 at 05:24.

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