RE: Battery powered tesla!

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Derek Woodroffe" <tesla@xxxxxxxxxxxxxxx>

Harvich,

	RE Tiny Tess

	All of the details of tiny tess are on the web site..
http://www.roffesoft.co.uk/tesla/tinytess/tinytess.htm

The circuit for the driver is here
http://www.roffesoft.co.uk/tesla/tinytess/ttpsu.jpg

It is basically a modification of Steve Connors Flyback driver driving a
home made HV transformer in a full bridge to give 2.5 Kv output. The
Transformer is a small ETD core with a 4 turn primary and a 2000T secondary,
this is run at around 20Khz.

 The output from this coil is rectified in a doubler circuit and the two
doubler caps also form the primary capacitor of a standard static gap TC
circuit, This essentially means that the TC runs from 5Kv DC, but because
the supply is not smoothed before the primary cap, there is no DC quenching
issues. The coil therefore runs at about 3Mhz (due to its size) although it
is fed from the 20Khz supply.

The circuit should be fairly easy to scale up, all you would need is a
bigger core, mosfets and rectifying diodes or as you suggest connecting
multiple transformers together (each with their own rectification) to give a
higher wattage supply.

I avoided using real fly back's for two reasons, 1) the diodes in them are
not very good at coping with having a spark gap on their output, ( I have a
pile of ex-fly backs to prove this) and 2) they give much too higher voltage
for a small TC. (making 1/2" gaps between wires when your TC is only 2" in
diameter is a problem)

I never did go down the line of resonant charging, as when I calculated the
size of the inductor required, it was bigger than the coil itself.

I'm not sure what the problem is with the new electronic NST's, but I too
have heard that they are very easily killed by TC use. (I've never tried) I
suspect this is a problem with RF and or current spikes the secondary, but
I'm sure these could be overcome with a suitable rectification and filtering
scheme.
The Electronic NST's are also current regulated, maybe without any inrush
protection your primary C was taking too much current and shutting down the
NST ?

A coil that will resonate at 20Khz is certainly too big for me to build, and
I think you would have even more problems filtering out the unwanted noise,
as it would be at the same frequency as your source.

Derek