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Re: Pipe scraps




I was sort of asking a question and answering a question
at the same time.  The first part is a question about
Robert's primary i.e. inner diameter etc.

The second part is data on my photocopier transformer
powered system for Jeff Parisse.  I assumed that he was
on this list.  Is he?  Maybe I should have posted this
separately.
Barry

 ----------
|From: "tesla-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
|To: Benson Barry
|Subject: Re: Pipe scraps
|Date: Saturday, October 19, 1996 12:44AM
|
|<<File Attachment: 00000000.TXT>>
|Barry,
|
|Despite your alerting me, could you sort this one out?  It's kind of
|confusing, and I'm not sure about who's saying what.
|
|Chip
|=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|"Of all tyrannies a tyranny sincerely  exercised for the good of its 
victims
| may be the most  oppressive.  It may be better to live under  robber 
barons
| than  under  omnipotent  moral busybodies,  The robber baron's  cruelty 
may
| sometimes sleep,  his cupidity may at some point be satiated; but those 
who
| torment us for own good  will torment us  without end,  for they do so 
with
| the approval of their own conscience."    -   C.S. Lewis, _God in the 
Dock_
|=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|On Fri, 18 Oct 1996 Benson_Barry%PAX5-at-mr.nawcad.navy.mil wrote:
|
|>
|>
|>  ----------
|> From: Administrator
|> To: Benson Barry
|> Subject: RETURNED BY ADMINISTRATOR
|> Date: Wednesday, October 09, 1996 11:34AM
|> Priority: Low
|>
|> Microsoft Mail v3.0 IPM.Microsoft Mail.Note
|> From: Benson Barry
|> To:  "tesla-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
|> Subject:  Re: Pipe scraps
|> Date: 1996-10-09 11:34
|> Priority:
|> Message ID: 9DFAE58D
|> Conversation ID: 9DFAE58D
|>
|>
|---------------------------------------------------------------------------- 

|>  --
|>
|> 320mH!!!  really.  What is the I.D. of your primary (inside layer)?  Why 
the
|> 1 1/2" spacing?
|> Hydro corona hold off ring?  What is it?  Sounds toroidal?
|>
|>
|>
|> Photocopier transformers from Herbach & Rademan: 5 kV at 300 ma.
|> 1.  Move secondary high voltage lead away from the grounded high voltage
|> lead.  I cooked my first pair this way.  The transformers are engineered
|> strange.  I don't know why the leads were designed so close together!
|> 2.  Must have needle gap with tungsten rods (sharp) to keep the voltage
|> from getting too high.  The resonant rise is very high up to 2 X .
|> 3.  Must have humongous common mode choke to keep the needle
|> gap from going off at the high power levels.  i.e. 1" square X 3" X 2"
|> window
|> hypersil core with 50 + 50 turns of RG-58 (without the braid) wound on it
|> in the same direction.
|> 4.  I use a rotary gap across the output.
|>  ----------
|> |From: "tesla-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
|> |To: Benson Barry; "Tesla-list-subscribers-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
|> |Subject: Re: Pipe scraps
|> |Date: Wednesday, October 09, 1996 2:40AM
|> |
|> |<<File Attachment: 00000000.TXT>>
|> |From rwstephens-at-ptbo.igs-dot-netTue Oct  8 22:28:23 1996
|> |Date: Tue, 8 Oct 1996 22:15:49 -0500
|> |From: "Robert W. Stephens" <rwstephens-at-ptbo.igs-dot-net>
|> |To: tesla-at-pupman-dot-com
|> |Subject: Re: Pipe scraps
|> |
|> |>>From Benson_Barry%PAX5-at-mr.nawcad.navy.milMon Oct  7 21:40:08 1996
|> |>Date: Mon, 07 Oct 1996 07:03:00 -0400 (EDT)
|> |>From: Benson_Barry%PAX5-at-mr.nawcad.navy.mil
|> |>To: tesla-at-poodle.pupman-dot-com
|> |>Subject: Re: Pipe scraps
|> |
|> |>Robert,
|> |>Experienced indeed!  Such efficiency.  52" with 900 watts!  Way!
|> |>Awsome!  What are the specs on your micas (series, parallel, individual
|> |>value?)
|> |>I heard that you use really big chokes on your neon to protect it.  How 
is
|>
|> |>it
|> |>holding up?  How long have you run it?  What brand of neon do you have.
|> |>Is it new or used.  Primary, flat spiral or dish or?
|> |>
|> |>I used two 5kv photocopier transformers with a grounded center 
arrangement
|> |>which use about 2400 watts (using the 20 ampere breaker test).  I don't
|> |>know the number of turns but it has 5 lbs of #18 heavy formvar magnet
|> |>wire on it with .065uF polyproplene capacitor with a rotary gap.  I 
think
|> |>that the dent may be a detriment.
|> |>Barry
|> |
|> |
|> |Barry,
|> |
|> |This 52 inch distance claim is for the very occasional streamer that
|> actually
|> |does make it this far out to a flat grounded metal sheet.  Most of my
|> |streamers will strike such a target much more frequently at 42
|> |inches.  Still, I am impressed with even this for a system that stores
|> |less than 1.6 peak  Joules in the primary circuit.  With 15 KV RMS 
divided
|> |by the capacitive reactance of the 0.007 mfd system cap my charging
|> |current is actually only _ 594 watts_!
|> |
|> |My micas are 30 pieces of 0.002 mfd -at- 12400 Volts peak, in three
|> |parallel banks of ten in series, yielding 0.0067 mfd -at- 37,200 V peak.
|> |I had two of these go intermittent recently causing the coil to work
|> |less well, then well, then less well.  I actually had to build a
|> |small tesla coil that would run on a single one of these 0.002 caps
|> |and use it to test, one at a time, all thirty after disconnecting
|> |them by removing all the copper bus strapping..  They all passed the 
test
|> the
|> |first time around.  I raised the voltage and tried them all over again.
|> |Two failed to dead short mode almost instantly.  I replaced them with
|> |spares that also passed the more extreme test, put the bank back 
together
|> |and now no more trouble.  Took me over four hours to find and fix
|> |this though.  Someone posted a great information post about different
|> |capacitors a while back (I think Richard Hull?).  Said micas were
|> |lossy but their redeeming social value was that they could withstand
|> |the great heat that their loss generated, and that mica has a good
|> |high dielectric constant.  This bank of micas certainly works very
|> |well in this particular coil.  I only went to this much trouble
|> |because caps are hard to find and I found this great lot of micas for
|> |$5.00 each, which still put me in fair shape compared to the cost of
|> |a single made to order commercial tesla cap.
|> |
|> |My primary falls under 'other'.  It is a two layer short solenoid
|> |with about 1.5 inches between layers.  Total 24 turns, 12 per layer.
|> |My system tunes at about 16 turns.  It's wound with #8 AWG PVC
|> |covered stranded wire.
|> |
|> |Yes, it's true what they say.  This kid uses large value air core
|> |chokes.  This coil has a 320 mH choke in each leg of the Jefferson
|> |neon.  Run times are as long as 2 minutes per run.  I've accumulated
|> |maybe 1/2 hour total run time on this system without transformer failure 
so
|> |far.
|> |I also run a blunt needle point safety gap across the transformer output
|> |gapped at 1.125 inches, it fires every several seconds or so.
|> |
|> |Toroid is a  3 X 24 inch commercial, smooth aluminum Hydro corona hold
|> |off ring.
|> |
|> |You can see a single photo of this small system in picture stc01rws.jpg 
in
|> my
|> |file at ftp://nic.funet.fi/pub/sci/electrical/tesla/pictures/rws.
|> |The donut topload in this photo is a smaller 3 X 18 incher.
|> |
|> |Sounds like you are using the same photocopier transformers that Jeff
|> |Parisse <jparisse-at-ddlabs-dot-com>  is experimenting with.  You might want to
|> |touch base with him.  As a matter of fact, I just sent Jeff a pair of
|> |my Mega-Henry brand RF chokes for his coil.
|> |
|> |regards,
|> |
|> |rwstephens
|> |
|>
|