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tesla coil primary wire

Discussion in 'High Voltage' started by lokeycmos, Dec 16, 2011.

  1. lokeycmos

    lokeycmos New Member

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    so im on a really tight budget. im working on my primary coil right now. im probly not going to be able to get copper tubing, which is ideal. im probly goona have to use solid single strand wire. will this affect the performance? what guage should i use? 12 guage is the easiest to find. just looking for your input on this. ty
     
  2. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    Haha, I had the EXACT same problem when I built mine. 3/8 inch copper tubing cost about $2.50 a foot, and for 50 feet of it, that was a little steep. I have used 12 gauge wire in the past (the type used to wire houses), and it worked okay. I would recommend you keep your eyes open for larger wire or tubing, though. Generally, 1/4-1/2 inch wire/tubing is ideal, as the resistance will be lower and more energy can be transferred from the capacitor to the secondary coil. I have heard that some refrigerators have some fairly thick tubing, so that is something else to look into. You can often find old refrigerators just scrapped and you can get parts from them for free. Just beware of the ones that use freon. You don't want to get any of that stuff on you :p

    But for the time being, 12 gauge wire should be fine.

    Regards
     
  3. gary350

    gary350 Well-Known Member

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    1/4" copper tubing works fine. If you buy refrigeration tubing it is 1/2 the cost of water pipe tubing. Copper wall thickness is 50% thinner less copper mean less cost. It bends easier when making the coils.

    Be sure to put a strike rail around the outer edge of the primary about 2" above the primary. Connect the strike rail to ground. If any HV arcs try to strike the primary they will hit the strike rail this protects your neon from HV. Look at the strike rail in the TC on the right side of the photo. The strike rail is 1 turn of 1/4" copper tubing the ends are "NOT" connected together they need to be about 1/2" from touching.



    [​IMG]
     
    Last edited: Dec 21, 2011
  4. dave

    Dave New Member

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  5. lokeycmos

    lokeycmos New Member

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    why are the ends not connected?
     
  6. gary350

    gary350 Well-Known Member

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    A strike rail is acts like a 1 turn coil if the ends were connected it would be a dead short.
     
  7. unclejed613

    unclejed613 Well-Known Member

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    .... and a shorted turn is on the bad list.

    for the same reason, you never mount a toroid transformer to a chassis where the center bolt makes electrical contact on both ends to ground....

    for some strange reason the Marconi spark gap transmitters (an adaptation of the Tesla coil) used shorting strips on the tap switches of the tuning inductors.... and somehow it still worked (although there must have been huge amounts of energy lost in the shorting strips). maybe this partially explains why the common theory was that shorter wavelengths than 200M (1.5Mhz) were considered to be useless for long range communication, the shorter the wavelength in those transmitters (and receivers, which used the same tuning techniques), the more taps connected to the shorting pole on the switch (wasting that much more energy).

    it's interesting to note (but i've never heard of it being enforced) that "B" type emissions ("damped" spark gap generated RF) are forbidden by the FCC.
     
    Last edited: Dec 27, 2011
  8. gary350

    gary350 Well-Known Member

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    My 10" TC makes 12 foot long sparks running at 12 KW. A circle of sparks around the 3 ft diameter top load makes a 27 ft circle of sparks and arcs in my yard. It sets off every security alarm system for a 4 block radius from my house. It sets off motion detector lights too they flash like strobe lights. Automatic electric garage doors go up and down none stop changing directions none stop too. It is not very bad on the TVs in the neighbor hood it pretty much wipes out all TV within about 100 ft from the TC. My house is the only TV that will not receive anything but static. I run this about 30 seconds at a time then stop for a few minutes then run it some more.

    [​IMG]
     
    Last edited: Dec 27, 2011

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