RE: DC TC in November Pop'Tronics

I've had that issue awhile and I have examined the spark gap arrangement. I
like it! I plan to use brass cap nuts on threaded shafts (for a round gap
rather than their flat bolt head) and each with a compression spring to
permit independent gapping. Seven gaps at .03 for a total of .21 to start
with. Then it will go in a box with a muffin fan for quenching. Frankly, it
makes more sense than copper tubes. I'll let everyone know what happens. My
first coil....

cheers, y'all

Tech Ted from Texas

Subject: DC TC in November Pop'Tronics

Original Poster: Kevin Ottalini <ottalini-at-mindspring-dot-com> 

	I just picked up the November issue of Popular Electronics with
a front-page feature article about a Solid-State DC driven Tesla coil
and a great historical article about Tesla himself.

The design uses a 555 timer and two FET-driven car ignition coils with
a multi-point static spark gap and a polyethylene/aluminum flashing
dry capacitor.

The input power is a 25V, 2A transformer, and it puts out 6" to 8"
sparks according to the article.  The author is Charles D. Rakes.
He also did an earlier article: HANDS-ON ELECTRONICS, Oct. 1988, Vol5,
No.10, SOLID STATE TESLA COIL. 24" tall secondary, uses 2N3055
transistors and automotive induction coil supply

The pupman archives (via Richard Quick) also list another article:
(October 1992, Popular Electronics pp 69-71, Fun With Tesla Coils)

Unfortunately, there were no real photos of the assembled unit or of
it running.

The capacitor is curious, with only 1" margin at the edges (2" overall
for 30+kv) and no oil.  The rest of the design is reasonable and has
some interesting features, especially since this is the first design
I've seen that really uses fet-driven car ignition coils.

* Kevin Ottalini            *
* WhoSys / Who Systems      *
* High Voltage with Style!  *
* ottalini-at-mindspring-dot-com   *
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