[Prev][Next][Index][Thread]

Re: H.V. Transformers



Subject:  Re: H.V. Transformers
  Date:  Fri, 9 May 1997 02:34:46 +0300 (EET DST)
  From:  Kristian Ukkonen <kukkonen-at-cc.hut.fi>
    To:  Tesla List <tesla-at-pupman-dot-com>


>   From:   "Robert W. Stephens" <rwstephens-at-headwaters-dot-com>
> have found them to be very intolerant of Tesla coil type service, 
> somewhat moreso than the generally beefier and notoriously fragile
> neons. 
> 
> Try an experiment.  Put a 500 pF doorknob cap from each terminal of 
> your 23 mA, 10 kV ignition xfmer to case ground and plug it in.  In 
> less than 60 seconds you will hear frying/boiling inside and will 
> probably have also within this short time have a shorted secondary.

I really can't see the point here. What you are most propably doing is
over-voltaging the poor xformer by setting a resonance between xformer L
and cap C.. You can kill most xformers this way. 

SO: for bypassing use resistors between xformer HV-outputs and those
.5nF
caps. This will effectively lower Q of circuit and prevent excessive
resonant rise. I do use 1k ohm power-resistors. 

> Merely 500 pF starts to send these into 60 HZ resonant rise but I 
> haven't measured how much.  The same caps tested today on a common 15-at-30 
> neon produced a 500 volt secondary voltage rise above the nominal 8000
> volts measured on each leg.

Just luck. With poor luck you might have fried the neon as well.

> hard way for a very early coil.  You are correct, these are an 
> alternative source for builders of small coils to neons, but they are 
> rather electrically fragile.  They also are not as easy to bolt down 
> mounting wise as neons.

They ARE a way to get 10kV at countries that don't have neons with more
then 8kV of voltage. Count Finland in for a list of those countries.

   Kristian Ukkonen.

-