Re: BetterCapacitors

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "rheidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

Terry: Salt water and mmc have real advantages. My students and I use
stack/roll capacitors. We use 4 Mill flat bag stock 2 x 4= 8 Mill  and 6
wrap thick for 48 Mill total around 10" Al flashing cut into plates and
connected with 1" Al straps and POP rivets. With 3 gal mineral oil the total
cost runs about  $130 total in smaller cost units so students can build them
in stages. They take time to build, but they have real current punch and
don't have all the failier problems. They are 4 parallel units with 4 straps
each total 16 x 1" straps so a few hundred amps is no problem to power even
a poorly tuned TC to give light at first try  with a real bang.
   Robert  H

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Sun, 28 Jul 2002 13:04:15 -0600
> To: tesla-at-pupman-dot-com
> Subject: Re: BetterCapacitors
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Sun, 28 Jul 2002 13:05:36 -0600
> 
> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> 
> Hi Chris,
> 
> At 11:02 AM 7/28/2002 -0500, you wrote:
>> 
>> A MMC would be the best solution.In terms of size and weight... but I have
>> no data to support this conclusion just your guys recomendations....
> 
> Everyone gets MMC now days or goes for the cheap salt water caps.  The geek
> group has a nice plan for a real good salt water cap and they also sell
> nice MMC caps cheap.
> 
> www.thegeekgroup-dot-org
> http://geekgroup.yi-dot-org:81/
> 
> Looks like they are working on their site right now...  Give it a few
> days...  Maybe write Chris...
> 
>> 
>> so I need some opinions on a couple things
>> 
>> Is it worth it to route out a source for the thick 30mil PE plastic sheeting
>> ???
>> whats an average cost of a 15-20nf rolled cap?
> 
> I can't think of anyone who has made a rolled cap in a year or so now.
> When MMCs hit the scene, a number of people dropped their rolled cap
> projects right in the middle and made MMCs instead.  I think an MMC is like
> 1/4 the cost and 1/10th the effort...
> 
>> 
>> Whats the best source for mini caps... The geek group?
> 
> Yep.  They have 0.15uF 2000V polypropylene foil caps (Cornell Dubilier
> 942C20P15K) for about $3.50 each (not sure of price?).
> 
> http://hot-streamer-dot-com/TeslaCoils/MMCInfo/GeekCaps/GeekCaps.htm
> 
>> whats the recomended ratings for caps not from the geek group?
> 
> Polypropylene-foil construction, high-current high-voltage self-healing...
> See the list at:
> 
> http://hot-streamer-dot-com/TeslaCoils/MMCInfo/good-bad.txt
> 
>> when is the next geek group order going through?
> 
> Ask Chris :-)
> 
> "Christopher Boden" <chrisboden-at-hotmail-dot-com>
> 
>> 
>> anyone have a guess at much would it cost me in resistors and capacitors
>> from the geeks to build a 15nf to 20nf MMC?
> 
> See this chart:
> 
> http://hot-streamer-dot-com/temp/MMCcapSales.gif
> 
>> Where is a good page to get the math for doing up a MMC?
> 
> http://hot-streamer-dot-com/TeslaCoils/MMCInfo/mmcinfo.htm
> http://hot-streamer-dot-com/TeslaCoils/MMCInfo/MMCPower4.html
> http://hot-streamer-dot-com/TeslaCoils/programs/Mmccalc2.zip
> 
>> What type of resistors do I need to use?
> 
> "I" just get 10Meg ohm 1/2 carbon film types.  Yageo 10MH
> 
> http://www.digikey-dot-com/scripts/us/dksus.dll?Criteria?Ref=88368&Cat=30802464
> 
> They are used over they're voltage rating but they work fine.  I have a few
> thousand extra so write me and I'll send you a bunch for free.
> terrellf-at-qwest-dot-net
> 
>> Say I built a MMC to go with a NST 12kv60ma, if I buy another NST can I just
>> build another MMC and paralel it in with the other one? Or do I need to
>> reconstruct the entire unit?
> 
> You just simply parallel it up.
> 
>> 
>> I can probably figure out a lot of this if someone points me to the right
>> information, but I would really like the current opinions on capacitors. a
>> little help with the math wouldnt hurt either.....
> 
> http://hot-streamer-dot-com/TeslaCoils/MMCInfo/mmcinfo.htm
> 
> See the little DOS program at:
> 
> http://hot-streamer-dot-com/TeslaCoils/programs/Mmccalc2.zip
> 
> Also a Excel spreadsheet form too.
> 
> http://hot-streamer-dot-com/temp/MMCcalc2xls.zip
> 
> The thermal dissipation value for these caps that MMCalc2 asks for should
> be "22".
> 
> However, Mark Broker's chart at:
> 
> http://hot-streamer-dot-com/temp/MMCcapSales.gif
> 
> already has everything figured out for normal coil configurations.
> 
>> My salties are tough and work but I hate moving the big heavy darm things...
>> 
>> I have been wondering has anyone ever built a primary on one of those round
>> plastic sleds?
> 
> Sounds like a great idea!
> 
> Cheers,
> 
> Terry
> 
>> 
>> Thanks
>> Chris Dowdy
>> 
> 
> 
>