Re: Bypass Capacitors

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 NTAC> TAC> Message-ID: <9502081530.AA21703-at-grendel.objinc-dot-com>
 NTAC> Newsgroups: tesla.list

 NTAC> From Esondrmn-at-aol-dot-com Wed Feb  8 01:15 MST 1995
 >Received: from mail02.mail.aol-dot-com by csn-dot-net with SMTP id AB13832
 NTAC> (5.65c/IDA-1.4.4 for <tesla-at-grendel.objinc-dot-com>); Tue, 7 Feb 1995
 NTAC> 16:53:41 -0700
 NTAC> Date: Tue, 7 Feb 1995 18:34:45 -0500
 NTAC> From: Esondrmn-at-aol-dot-com
 NTAC> To: tesla-at-grendel.objinc-dot-com
 NTAC> Subject: Bypass Capacitors

 NTAC> Greetings tesla fans,

 NTAC> Does anyone know where I can get some high voltage bypass capacitors
 NTAC> for neon sign protection and filtering?  I read the choke1A.txt in the
 NTAC> rqdocs file. Someone is recommending three .003 mfd -at- 30kvdc in series
 NTAC> for each side (six total) for a net .001 mfd 90kvdc.  These might be
 NTAC> available in surplus shops somewhere but not in Spokane, WA.  I can't
 NTAC> find anything like this in Mouser or Allied catalogs.

 NTAC> Can I make these myself using left over materials from the rolled high
 NTAC> voltage tank capacitors?  I think I want somewhere around 500 to 700
 NTAC> pf. Will the .0625 polyethylene give me enough voltage rating?

 NTAC> Thanks, Ed Sonderman

 MG> I'd like to pass along a idea that I have used for years and works
 quite well for bypassing on neon transformers and eliminates looking around
 for "doorknob" style caps etc. An excellent bypass can be had by obtaining
 two pieces of .0625" clear Plexiglas with a dimension the same or slightly
 smaller than the side of the neon transformer. Clean the Plexiglas and the
 side of the transformer, then using clear Silicone caulk (RTV) put a thin
 flim on the plexiglas and stick it to the side of the transformer pressing
 slightly to remove air bubbles and let it dry, do this on both sides of the
 transformer. Now cut two pieces of aluminium flashing smaller than the
 Plexiglas by an amount that will provide about a .5" to .75" border around
 the edge of the flashing to the edge of the Plexiglas and leave a tab that
 will allow connection to one of the H.V. outputs on the transformer. Smear
 a thin film of RTV on the flashing and stick it to the plexiglas, let it dry
 and then put a coating of RTV over the flashing, or RTV another piece of
 Plexiglas over it. After its dry, bend the tap over and attach it to the
 transformer H.V. connector, you may also wrap the tab with tape of you like.
  What you have actually done here is built a bypass cap on each side of the
  transformer using the transformer case as one plate of the bypass capacitor
  the case becomes the "grounded plate" HDPE could be used, but I know of
  no way to "glue it" and it would'nt offer any advantage in this type of
  use anyway. Building a bypass this way will result in a bypass value of
  about 150-200pf which is entirely adequate, but if you wanted to, I see
  no reason why one could'nt add another plate. Try it, it works very well!

                                Mark Graalman TCBA#1399


... Alias, Mark the spark
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