Commercial Capacitor Rebuttal
Before I start, I want to apologize for this message being curt, but it is. I
feel very strongly about these capacitors being the correct ones for our
application. I've put a lot of time into this.
>Those capacitors yall are planning to buy seem a little shy on voltage
>to me. 35-40KV rms seems a little more like it, especially if you want
>to grow into them. Check out Maxwell Labs in San Diego for
>polypropylene caps marketed as "Double Ended Plastic Capacitors". They
>have a good in-stock selection and are OK priced. They also work great
>and do not get hot!
I'll try to put this nicely. BULL!!! I'm not saying what you found won't work.
But is it truely what a coiler idealy wants? Let me expand on this a bit.
I first experimented over a 6 month period or so with different capacitors, both
homebrew and commercial. So I learned a bit about what really works. I never
built a Hull rolled capacitor, only plate style. I built some small ones and
compared them to commercial ones of the same rating.
I have spoke to over a dozen people on this subject. I have also looked over
the specifications of capacitors used by many others, including professional
coiling companies. The people/companies that I have checked on the
specifications of the capacitors they use or talked to directly include D. C.
Cox of Resonance Research, Richard Quick, Ed Sonderman, Mark Graalman, Richard
Hull, etc., ect., etc. The list goes on a while.
I have spent HOURS on the phone discussing Tesla pulse capacitors with three of
the companies that are responsible for supplying 90% of these types of
capacitors in the United States. I touched base with several others. The
companies include NWL, Plastic Capacitors and Condenser Products. All of these
companies have extensive experience in Tesla pulse capacitors. NWL provides
capacitors to Richard Hull, Plastic Capacitors to Resonance Research, and
Condenser Products to most of the coilers, including Richard Quick. I have
discussed the following issues, AT LENGTH, with these companies' design
engineers; resonant rise, pulse per second, amps peak, loss factors, internal
inductance and resistance, RMS vs peak voltages, Q factors, etc., etc., etc. I
have also talked with them about what they see in failures with certain
transformers. These folks know what they are doing and understand a Tesla tank
I know that you can use a 15 KVAC RMS Telsa cap from one of these companies with
a 15KV transformer in a tank circuit, without failure. Ed Sonderman, for one,
uses a 15 KVAC RMS, .025 uF Condenser Products capacitor in his circuits. And
he beats the hell out of it with a 14400 VAC pole pig. Guess what? It doesn't
fail, with long run times. And there are many, many others, including the one
listed above that use them the same way; ie. - transformer voltage rating close
or matching Tesla pulse capacitor voltage rating. This will not work for any
capacitor with a matching RMS voltage rating, it needs to be a capacitor
specifically designed for a Tesla tank circuit.
Richard quick has a system that has 90 KVAC RMS rated capacitance (two 45 KVAC
RMS capacitors in series) in a tank circuit. This he built for two reasons.
First he wanted huge safety margins. Secondly, and the main reason, it was an
opportunity that arose due to a misfortune at Condenser Products. It was HUGE
LUCK for Richard. He really doesn't need this kind of safety margin. He will
The key is that the capacitor manufacturer build the capacitor specifically with
a Tesla tank circuit in mind. These manufacturers do exactly that. These are
Tesla tank circuit pulse discharge capacitors, not just pulse discharge
As far as higher voltage ratings go, I want to remind you that these caps are
rated in AC RMS, not just AC. So the peak voltage rating is considerably
higher. But, for posterity, let it be known that I spent time considering
higher voltage ratings. I looked at 30 KVAC RMS and 40 KVAC RMS Tesla pulse
capacitors. These units go for approximately $325 and $450 respectively. Those
prices vary with manufacturer. I have already considered safety factors in the
selection of our 20 KVAC RMS caps. These capacitors will probably be used by
coilers with 14400 VAC or 15000 VAC transformers. This is a great safety
margin. The next readily availably transformer voltage is a little under 23000
VAC, as Richard Quick uses. This would require that one goes to a 30000 VAC
capacitor. Rest assured, these capacitors will survive in up to a 20 KVAC
transformer powered Tesla tank circuit. I have a 1 year warranty assurance from
the manufacturer. They are aware we intend to use up to 20 KV in the tank
circuit, although most will choose 15 KV. They certainly would not give such a
written warranty with GREAT CONFIDENCE in that their capacitors will survive.
Since we will end up buying over 10, (the manufacturer is aware of the quantity)
they do not want to rework a bunch of their capacitors because of marginal
design. Rest assured, they are consevatively rated.
The comanpy you mentioned markets plastic capacitors. That fine. Your note
doesn't say anything about pulse discharge, RMS voltages, Tesla tank circuits,
etc. I ask you this, can they guaratee their caps in our application? Are they
Tesla pulse caps, hense high Q, high amperage peak, low inductance? The
companies I have talked to are experts in this. We are trying to build the most
efficient systems we can afford. These capacitors will provide this, WITHOUT A
If you ask around, you will find that Condenser Products is one of the highest
regarded companies in this area. And they are willing to support coilers and
back their product with a warranty.
So please, don't just blow off 2 months of my research with a simple sweeping
statement about voltage rating like "seem a little shy on voltage to me" without
expanding on it considerably. I am doing my best, with the help of many others,
to make sure we all have the correct product at the best possible price.
Again, my apology for being curt.