Re: Peak cap voltage, was 12kV, 30ma TC specs, 42" spark

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: Peak cap voltage, was 12kV, 30ma TC specs, 42" spark
From: Tesla List <tesla-at-stic-dot-net>
Date: Wed, 17 Sep 1997 00:27:23 -0500
Approved: tesla-at-stic-dot-net

From: 	Jason Judd[SMTP:Jason.Judd-at-anu.edu.au]
Sent: 	Tuesday, September 16, 1997 8:33 PM
To: 	Tesla List
Subject: 	Re: Peak cap voltage, was 12kV, 30ma TC specs, 42" spark

> Hi Jason,
>  
> > I am just starting to get good results with my 6" 15Kv 60MA setup. The
tank
> > capacitor is 14 nF (for 50Hz) rolled poly (two series 28 nF caps). The
best
> > I have done so far is 35". I am using a tripple gap system quenched
with a
> > microwave oven fan. What I have found is that to get the long sparks
the
> > gap must be made quite wide to take advantage of the resonant charging.
> > When I got to about 12MM (1/2") the terminals from my two 15Kv 30 MA
> > tranies started to arc to the case which is about 10MM from the edge of
the
> > HV insulator. I supose this is a good saftey gap and may well have
saved my
> > transformers.
> > 
> > My question is how far should I open the gap to take advantage of
resonant
> > charging ? he gap has never miss fired yet. It apears to me that I
should
> > set the gap to fire around the 30 KV mark. I'm not game to do this
because
> > my caps were not designed with this voltage in mind , but in the future
> > they will be.
> 
> What are your transformers designed to survive? You can always get 
> big sparks from neons if you push them.
> 
> Malcolm
> 
> 

Malcolm,

What do you mean what are my transformers desighned to survive. How can I
tell. I surpose when one fails I am at the limit ;-). They are rated at
15Kv 30Ma each. The peak voltage would be about 21 KV. Are you telling me
(or trying to say nicely) that I am headed for trouble on this path ?

I think that a safer path might be to build more caps and maybe get another
couple of transformers so I can run at a lower voltage as Tom McGahee has
sugested.

Also I have noticed that the best sparks from my system occur as the first
spark after switch on. Sparks after this are never as long. I would put
this down to the gap ,but the spark length drops off by about 20 % within
.5 of a second.

Thanks very much everyone for all the input on this subject.

Cheers,

Jason