Re: [TCML] Spark gaps, Solid state switches and diodes

[DC Cox <resonance@xxxxxxxxxxxx>]

I use a 2.5" tee.  I found the smaller ones will melt too easily.

The SISGs were really designed for 2 mots in series, ie, 4 kV.  You would
have to spend approx $150 or more on parts for a 15 kV type.

Dr. Resonance




On Thu, Jan 29, 2009 at 11:15 PM, Stephen Hiscock
<stephenhiscock@xxxxxxxxx>wrote:

> Thanks for the suggestions.
> You must have read my mind (or perhaps I read yours).
> I brought home a T-section pipe with an inspection cover - which I think
> will fit a standard 1/2 inch copper pipe into each side - which I have lots
> lying around the house.
> Thanks I will try that.
> But I'm still interested in the SISG.
> does anyone know how suitable the standard design is for my 15,000 NST
> transformers - and what kind of current are they designed for.
>
> Thanks
> Stephen
>
> DC Cox wrote:
>
>> If you want a quck and inexpensive fix try my hyperbaric sparkgap.  At
>> this
>> power level perhaps two in series, but  try one first.  The vac. cleaner
>> motors are nearly or sometimes free at large
>> vac cleaner repair shops.  Plbg fittings from local large hardware store
>> (usually brass fittings), and some 3/4" copper pipe (Home Depot).
>>
>> You should disconnect your power xmfrs and test all individually to be
>> sure
>> one hasn't died.
>>
>> The SISG gaps also provide high performance, but at a price.
>>
>> Dr. Resonance
>>
>>
>>
>>
>> On Thu, Jan 29, 2009 at 8:46 PM, Stephen Hiscock
>> <stephenhiscock@xxxxxxxxx>wrote:
>>
>>
>>
>>> Hey guys, my name is Stephen,  I've just joined this email group.
>>>
>>> I work as an electrical Engineer and I've been playing with Tesla Coils
>>> and
>>> High voltage for about 15 years or so, and built a fairly powerful Tesla
>>> coil about 10 years that made over 1 metre (3-4 feet ) sparks.
>>>
>>> It was just Neon Sign powered (I had 6 in parallel) and had a
>>> conventional
>>> spark gap, but it never performed as well as I would like. I fired it up
>>> the
>>> other night after dusting it off (it had been in my garage for a bout 5
>>> years), and it performed dismally only getting about 1-2 foot sparks.  I
>>> played with the spark gaps etc and got it performing a bit better, but
>>> nothing like it used to go.
>>>
>>> I'm thinking that I'm wasting a lot of energy in my spark gap. in fact
>>> tow
>>> nails hammer into wood seemed to perform the best (quenching issues?)  So
>>> I
>>> went online and after a while came across Terry Fritz's plan for a solid
>>> state spark gap, but his plan only seemed to be for a relatively low
>>> powered
>>> MOT tesla coil. (a few hundred watts)
>>>
>>> I'm wondering if anyone who has had first hand experience with these
>>> solid
>>> state spark gaps (SISG) could help me answer a few questions
>>> * My transformers put out 15,000 Volts at 30mA each x 5 (or 6 if the fuse
>>> doesn't blow ;-) ) so how many will SISG's will I need
>>> * how reliable will his general design be with my coil. (obviously I will
>>> need more in series - but will I need to parallel them as well??
>>> * Is there an easy way / simply formula to calculate how much current
>>> will
>>> be flowing peak? (800A or 8000A) - depends on resistance or capacitance
>>> or
>>> inductance? - I currently don't have an oscilloscope at home I can use.
>>> * How much power gets wasted in the reverse diodes - normally the voltage
>>> drop across a diode is 0.7 volts - so does that mean if I'm getting 1000A
>>> peak average in the primary I will be wasting about 700 watts as heat
>>> across
>>> the devices and possibly more depending on how many devices I have? or am
>>> I
>>> missing something? - this would seem worse than the conventional gap -
>>> but
>>> everyone seems to rave about the performance of SISG and DRSSTC coils.
>>> perhaps its about peak energy levels (not average) and then 700 peak
>>> watts
>>> compared to 15MW peak energy  is not much?
>>> I think I just answered my own question. ;-)
>>>
>>> Sorry for so many questions, but you guys seem to like answering
>>> questions
>>> - and I've been enjoying the discussion - so hopefully I've added
>>> something
>>> more to chat about.
>>>
>>> so to be simple - how easy will it be to scale his design (SISG) to my
>>> coil
>>> or will most components need to be upgraded.
>>>
>>> Stephen
>>>
>>>
>>>
>>> _______________________________________________
>>> Tesla mailing list
>>> Tesla@xxxxxxxxxxxxxx
>>> http://www.pupman.com/mailman/listinfo/tesla
>>>
>>>
>>>
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>
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