FW: Spark Gap Idea

From: 	DR.RESONANCE[SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent: 	Monday, June 23, 1997 10:05 PM
To: 	Tesla List
Subject: 	Re: Spark Gap Idea

To: Jim Buck

Sounds like you are in the ball park on your voltage.  The spark distance
is almost entirely dependent on the type of spark gap electrodes you are
using.  For a quick test use some 1 cm balls (like old electric motor ball
bearings glued to two small shampoo bottles for insulators) and note the
max. spark discharge.  You can then look up this in the Handbook of
Chemistry and Physics which is available in any medium to large library. 
This contains a chart for exact potential between spheres of various cm

If you can haul this setup to a local TV repair shop they usually have a 40
KV HV probe for checking the output to the picture tube on TV's.  They
could check it for you in a few minutes and give you the exact potential
within 1-2%.

Hope this helps.


> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-poodle.pupman-dot-com>
> Subject: Re: Spark Gap Idea
> Date: Monday,June 23,1997 6:14 PM
> From: 	Jim[SMTP:jwbuck-at-loclnet-dot-com]
> Sent: 	Monday, June 23, 1997 10:30 AM
> To: 	Tesla List
> Subject: 	Re: Spark Gap Idea
> > 
> snip
> > Ingenious idea there Jim! I would be a bit concerned at to the maxium
> > voltage you gap can handle though. As I remeber the old variable
> > capacitors they worn't built for high voltage, so keep an idea on the
> > insulation! What voltage transforer are you using with that gap?
> I'm not sure about the voltage.  I'm using 2 high output ignition coils
> connected in series.  I can get a little over 1/4" spark across the gap
> so voltage is probally around 10 to 15 KV???
> > 
> > > Instead of putting a knob on the shaft to rotate the gap I cut a
> > > at the end of the shaft so I can use a long screwdriver to adjust the
> > > gap while the coil is running which may be a stupid idea but I
> > > gotten zapped yet.
> > 
> > Jim, if your feeding that gap at 60 Hz and there is more than 0.1 amp
> > available, you are playing Russian roulet (sp.?)! Do yourself a favor
> > and use an insulated (fiberglass shaft) screwdriver! As far as I know
> > there is only one official death associated with a Tesla coil, lets
> > keep it that way!
> Thanks for the warning...I probally need it!  I know its not a good idea
> to mess around with the HV when the coil is running but I am using a
> insulated screwdriver; It has about a foot of fiberglass and the blade
> stuck into the end is less than 1/4" deep. I also make sure I am well
> insulated and only have one hand anywhere near the HV. I guess I should
> have been more precise in my orginal post but I was just assuming that
> an insulated handle would be standard procedure working with any HV..
> Jim