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Re: Cap Formulas (fwd)



Original poster: List moderator <mod1@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Wed, 13 Dec 2006 21:39:13 -0600
From: Stan <wsmg@xxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Cap Formulas (fwd)

You Go Victor,

 My attitude is if Maxwell or anybody else can do something that works, 
I can also. I also have been thinking about a better process to build my 
own. I wish I had a few more hours...

Stan

Tesla list wrote:

>Original poster: List moderator <mod1@xxxxxxxxxx>
>
>
>
>---------- Forwarded message ----------
>Date: Wed, 13 Dec 2006 22:23:00 -0500
>From: Victor Yoo <vlysvc@xxxxxxxxxx>
>To: 'Tesla list' <tesla@xxxxxxxxxx>
>Subject: RE: Cap Formulas (fwd)
>
>I beg to differ! I think that they will be cheaper to build than MMC's!
>And Yes after the beta testing and abusing by the select few and they are
>perfected I will offer a warrantee! And as far as any section seeing to High
>of voltage, I will cross that road when it comes. If I have to wire two in
>series than so be it! I have located the parts to make the roller for just
>over a few hundred bucks. And I have the materials to make the fixture
>already. The roller will have a bath of Acetone that the plates and
>dielectric will pass through before it is rolled to insure that they are
>clean and free of any contaminants. 
>
>Victor
>
>
>-----Original Message-----
>From: Tesla list [mailto:tesla@xxxxxxxxxx] 
>Sent: Wednesday, December 13, 2006 5:36 PM
>To: tesla@xxxxxxxxxx
>Subject: RE: Cap Formulas (fwd)
>
>Original poster: List moderator <mod1@xxxxxxxxxx>
>
>
>
>---------- Forwarded message ----------
>Date: Wed, 13 Dec 2006 15:20:56 -0500
>From: "Lau, Gary" <Gary.Lau@xxxxxx>
>To: Tesla list <tesla@xxxxxxxxxx>
>Subject: RE: Cap Formulas (fwd)
>
>Why would it be useful to remove oils from handling, if it will
>ultimately be submerged in oil?
>
>But more importantly, rolled caps have gone the way of the buggy whip.
>While you may have a relatively good way to build them, no one will want
>them.  No coiler who is aware of the state of the art of coiling is
>going to buy a DIY rolled cap over an MMC, and it's doubtful that the
>price or reliability could be made competitive with an MMC.  The only
>appeal of a DIY rolled cap is that YOU made it, with no charge for your
>labor.  If someone else makes it, their significant labor and equipment
>investment is not free, and no personal pride.  Then there's that nasty
>business of if you make and sell it, does it come with any sort of
>warrantee?
>
>Most HV commercial caps are made of multiple sections wired in series,
>to keep any one section from seeing too high a voltage.  I think
>something to do with corona inception voltage - an unavoidable situation
>where a dielectric of any quality or thickness will degrade and fail if
>exposed to the corona that occurs if the voltage is too high.  A rolled
>cap must take the same thing into consideration.
>
>Gary Lau
>MA, USA
>
>  
>
>>From: resonance <resonance@xxxxxxxxxxxx>
>>To: Tesla list <tesla@xxxxxxxxxx>
>>Subject: Re: Cap Formulas (fwd)
>>
>>
>>
>>
>>Sounds like a good solid plan.  Be sure to wear gloves and wipe your
>>    
>>
>plates
>  
>
>>and dielectric down with acetone before winding.  Need to keep any
>>    
>>
>oils
>  
>
>>out --- someone may have handled it before you received it.
>>
>>Dr. Resonance
>>
>>
>>
>>Hi Doc.
>>
>>Here is the process that I was intending on doing to make my caps,
>>
>>1 Use the BEST dielectric available
>>      (Compromise of best properties to cost)
>>2 Use aluminum flashing 20 x xx x .025 or better (max .030)
>>3 Use Sch 80 PVC tubing and end caps
>>4 Use a Robinair 4cfm vacuum pump
>>5 Sandblast the edges of the flashing while it is still in a tight
>>roll to round off and smooth all the edges
>>6 use acetone to bath and clean the flashing
>>7 use the compatible solvent to bath and clean the dielectric
>>      (Purchased in rolls)
>>8 use great to best impregnating oil
>>9 Design and build a machine that will wind two plates and two layers
>>of                  dielectric simultaneously with proper back tension
>>to provide a very tight roll. (14-20" wide flashing and 18-24"
>>dielectric)
>>10 the termination will be provided on both ends of each plate
>>(totaling four 1.5" strips) by cutting the sheet and folding the strip
>>in the proper direction to create connections that exits on one end.
>>11 make a vessel as such that it will withstand a min vacuum of 25hg
>>12 Use 3/8 brass hardware for termination and epoxy or better for
>>sealing the terminations
>>13 Add a vacuum and oil fill port to the vessel
>>14 after the roll is made, terminated and sealed in the vessel
>>I will pump it down to 25hg and then draw in the oil.
>>15 after the first pump down and fill I will do it again two more
>>    
>>
>times
>  
>
>>or until there is about 2" of room left in the top covering the roll
>>    
>>
>at
>  
>
>>least by 2"
>>16 use nitrogen or the compatible inert gas on the fourth and final
>>pump down, fill the remaining space in the vessel with gas.
>>17 provide an externally mounted reservoir of gas for expansion and
>>contraction caused by changes of temp.
>>18 break her in at 1/4 power then 1/2 power then at 3/4 power and the
>>real glory of full power! (14.4kv @ 10-15kva pig)using a dummy primary
>>    
>>
>and
>  
>
>>SRSG @ 480bbp.
>>19 Provide a few to a select few at material cost to test and abuse.
>>20 once proven provide them to Tesla Junkies like us at a reasonable
>>price and to spec.!
>>
>>What do you think, will it due?
>>
>>Victor
>>
>>
>>
>>-----Original Message-----
>>From: Tesla list [mailto:tesla@xxxxxxxxxx]
>>Sent: Saturday, December 09, 2006 10:52 PM
>>To: tesla@xxxxxxxxxx
>>Subject: Re: Cap Formulas (fwd)
>>
>>Original poster: List moderator <mod1@xxxxxxxxxx>
>>
>>
>>
>>---------- Forwarded message ----------
>>Date: Sat, 9 Dec 2006 20:11:37 -0700
>>From: resonance <resonance@xxxxxxxxxxxx>
>>To: Tesla list <tesla@xxxxxxxxxx>
>>Subject: Re: Cap Formulas (fwd)
>>
>>
>>In US units the equation is:
>>
>>
>>        C   =  KA/d x (n-1)
>>
>>
>>where C is in picoFarads
>>
>>K is dielectric constant of the dielectric
>>
>>A is total area of one plate in square inches
>>
>>d is thickness of dielectric
>>
>>You just insert your data and solve the above equation for area.
>>
>>
>>If you plan on using a pole xmfr I definitely would NOT use mylar.  I
>>recommend either PP (polypropylene) or PE (polyethylene) as a better
>>dielectric choice.  About 90 mil thickness if only one thickness,
>>    
>>
>otherwise,
>  
>
>>use multiple layers (5) of 20 mil sheets.  7 mil mylar will not last
>>    
>>
>very
>  
>
>>long on a pole xmfr.  RF currents produce heat and edge-tracking both
>>    
>>
>which
>  
>
>>can destroy a HF RF cap rapidly.
>>
>>Also, if rolling your own, be sure to use extended foil construction.
>>    
>>
>Leave
>  
>
>>a very generous margin on each dielectric edge (3 inch min on each
>>    
>>
>side).
>  
>
>>Wear plastic gloves as the salts on your skin are very conductive and
>>    
>>
>will
>  
>
>>cause your cap to "edge track" at RF frequencies --- the number one
>>    
>>
>cause of
>  
>
>>HV cap failures.  Vacuum evacuate the cap prior to adding the
>>    
>>
>protective
>  
>
>>xmfr oil.
>>
>>If you need xmfr oil contact me off-list.  I carry it in 55 gal drums
>>    
>>
>and
>  
>
>>could supply a gallon.
>>
>>Dr. Resonance
>>
>>
>>
>>
>>Can any one help me with calculating the required area (length of
>>    
>>
>plates) to
>  
>
>>make a rolled cap using the following;
>>
>>
>>
>>20" wide by XX long aluminum flashing
>>
>>24" wide x .007" thick x XX long Mylar film
>>
>>
>>
>>With a dielectric constant of 3.0 and a puncture voltage of 7500v I
>>    
>>
>figure
>  
>
>>that I can make two 0.1uf @ 52.5kv for a total of 0.2uf for my 14.4kv
>>    
>>
>10kva
>  
>
>>pig.
>>
>>I will be immersing the roles in mineral oil.
>>
>>
>>
>>Any ideas or comments?
>>
>>
>>
>>Victor
>>
>>
>>--
>>No virus found in this outgoing message.
>>Checked by AVG Free Edition.
>>Version: 7.5.432 / Virus Database: 268.15.15/579 - Release Date:
>>    
>>
>12/7/2006
>  
>
>>1:31 PM
>>
>>
>>
>>
>>
>>
>>--
>>No virus found in this incoming message.
>>Checked by AVG Free Edition.
>>Version: 7.5.432 / Virus Database: 268.15.15/581 - Release Date:
>>    
>>
>12/9/2006
>  
>
>>3:41 PM
>>
>>
>>--
>>No virus found in this outgoing message.
>>Checked by AVG Free Edition.
>>Version: 7.5.432 / Virus Database: 268.15.16/582 - Release Date:
>>    
>>
>12/11/2006
>  
>
>>4:32 PM
>>
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>>
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>>
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