Re: Help making tesla coil and jacobs ladder

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Mddeming-at-aol-dot-com>

In a message dated 2/13/02 7:26:06 PM Eastern Standard Time, tesla-at-pupman-dot-com
writes:
Welcome, Robb,
         (Comments interspersed)

>
> Hello folks, im new to the mailing list.
>
> I am seeking advice and guidance on building a Tesla coil using
> a 12,000 volt 30ma Neon Sign transformer.
>
> I have searched the net, and while I can probably figure it out,
> I must admit that im not as electrical savy as I'd want, to undertake
> designing one myself.
>
> I dont want to burn up the transformer, as I want to use it for other
> projects as well, and I dont want to do anyhting that can get someone
> hurt.
>
> Can anyone out there help me / tell me how to construct on?
> Im not shooting for any goal of "50 inch arcs" or anything, just a
> funtioning tesla coil that wont hurt anyone.



Any Tesla coil will hurt a careless person sooner or later. A jacobs ladder can
be just as deadly, if not treated with proper respect.

>
> Also, i want to make a jacobs ladder. Correct me if im wrong, but cant
> I just take 2 coat hangers, bent away from each other, and shove them
> in a piece of pine wood.  Position the bottom/closest point so its close
> enough its not that hard for the 12kv to arc across, then let air
> ionization and the spread of the wires do the rest.



At 10,000 V and above wood can exhibit some pretty nasty conductive properties.
Actually, its the moisture content of the wood, and soft woods tend to be
nastier. I would use a block of plastic or standoff insulators. Alternatively,
you can fasten the wires firmly to the high voltage terminals and let your
ladder be a suspended sculpture.

>
> PS, this transformer, i bought on ebay, is a Franceformer.
> Its completely potted in a steel casing.  Does it have any capacitors
> inside that I need to worry about, or is it probably just a transformer?
> Also.. I need output wires for the unit.  Any suggestions?
> Will I need to use spark plug wires, to handle the voltage?


Unless it says "Power Corrected" of "High Power Factor" on the case, there
should be no problem with extra components.


>
> Thanks much folks, I appreciate it.
>
> -Robb



Try this for starters:

Primary-
         6.5" id 0.25" tubing, 0.25" between turns (0.5" c-c) 15 turns
Tank Cap ~0.0065uf to 0.0067uf
Secondary 4.25 to 4.5" OD x 18" ~980ft #24AWG magnet wire
Multi-section static gap 10 -at- 0.025" or equivalent.
With a 3 x 18 toroid, this should resonate near 430 Khz.
This wont break any world's records, but it should be a good solid starting
point.

Matt D. 
G3-1085