RE: [TCML] Suggestions for a mini-TC?

["Derek" <tesla@xxxxxxxxxxxxxxxxxxxxxxxx>]

Jason,
	I have built all sorts of mini TC's both SG RSG SSTC DRSSTC & a
magnifier..

	Take a look at http://www.extremeelectronics.co.uk/coils for more
details & contact me if you need any more information

	Cheers

		Derek
 

-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of Jason Goodman
Sent: 24 December 2007 19:41
To: Tesla Coil Mailing List
Subject: [TCML] Suggestions for a mini-TC?

I'm thinking of trying to build a very small spark-gap-style tesla
coil: something with a secondary perhaps 1 inch in diameter and 6 inches
long, topped with a toroid about 4 inches across.  The whole thing should
fit in a shoebox, and ideally throw sparks about 4-6 inches.  One hell of a
desktop toy for the office!

I played with JavaTC a little, and it looks like something with the
following specs should work:
Toroid: 1 inch minor, 4 inch major diameter Secondary coil: 1 inch diameter,
6 inches long, 30-AWG wire, 500 turns Primary coil: flat coil, 10 AWG, 5
turns, min diameter 3 inches, max diameter 7 inches Primary capacitor:
0.0012 uF Resonant frequencies tuned at 2.3 Mhz

If I want sparks 4-6 inches long, I read from this list that length =
0.85 sqrt(power), so power should be about 50 watts.
To easily exceed the breakdown voltage of 30 kV/cm in air near the toroid, I
need to get the toroid up to about 100 kV.

I've got several questions about other aspects of the coil:

1) What voltage should the primary circuit be designed for?  Just kind of
vaguely scaling things down from the sort of coils I've seen here and used
before, I figure something like 1 kv should be sufficient, and will keep the
components reasonably small and compact, but I'm just guessing.

2) What should I use for a power supply?  To deliver 50 watts of power, I
want something in the ballpark of 120 V, 1 A on the supply side, and 1 KV,
100 mA charging the tank capacitor.  This seems kind of overpowered to me,
but what do I know.
    a) anyone know of a transformer with vaguely this sort of spec?
    b) If not, can I make one?

3) With such a low voltage in the primary circuit, I'm thinking I'll have
trouble building a reliable spark gap.  Would a solid-state switch (IGBT or
SCR) make more sense in this circuit?

4) This needs to be a desktop plug-in model, so I can't exactly ground it
using a stake in the earth.  Given its smal size, will I be able to filter
it enough to be able to hook the secondary up to the mains ground line?
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla