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Re: Rebuilding a neon
MIKE,
I am currently in the process of rebuilding a jefferson 12/60. I got the
core out by the following method:
1. Place outer core on top of two cement blocks so that straight section is
free to drop.
2. Tie 2 ropes around straight core piece to hold it and the windings when
the whole thing drops.
3. Get a round punch with a flat end (about 1/2" ).
4. Place the punch on one end of the straight piece just inside the outer
core and hammer a little.
5. Do the same thing at the other end of the straight core piece.
6. Keep going back and forth until the center piece comes out (it is very
tight).
7. Put the windings in an ultrasonic cleaner with a solvent that dissolves
tar (toluene worked for me).
8. After about 10 sessions (2-4 hours each with fresh solvent) in the
ultrasonic cleaner they will be
ready to coat with insulation.
9. I used red glyptol because it worked fine in my rebuilt 12/30 france. I
layed the winding on some
flat screen to let it drip. I brushed the red glyptol into the
windings until it began dripping out
the other side and then stopped until it dried. I kept doing this
until the red glyptol stopped
dripping out the other side. I put on just enough more to fill up to
the edge of the paper. Then
the winding is turned over and this side is filled up to the edge of
the paper also. The finished
winding thus produced was as hard as a brick. When I get to my third
transformer (15/60
jefferson) I will try slow curing epoxy to see if the coil can be
coated without the formation of
bubbles.
10. Then solder 40 kv wire (or whatever is handy hv wire) to fine coil lead
wire and wrap lead and
entire winding with 1/2" wide kapton tape using generous overlaps.
11. For the 12/30 france I used 1/16" teflon sheet in place of the original
mica sheets between the
coil and core after reassembly.
I havent put the core back into the 12/60 jefferson yet. I plan to do it
the same way that I took it out
with a hammer and round punch. I will let you know if I am successful.
Barry
----------
|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: Rebuilding a neon
|Date: Tuesday, August 06, 1996 11:39PM
|
|<<File Attachment: 00000000.TXT>>
|> Subject: Rebuilding a neon
|
|From bturner-at-apc-dot-netTue Aug 6 11:21:00 1996
|Date: Tue, 06 Aug 1996 00:06:22 -0700
|From: open_minded <bturner-at-apc-dot-net>
|To: tesla-at-pupman-dot-com
|Subject: Re: Rebuilding a neon
|
|Tesla List wrote:
|>
|> >From mhammer-at-midwest-dot-netSun Aug 4 13:25:47 1996
|> Date: Sat, 3 Aug 1996 23:58:31 -0500 (CDT)
|> From: Mike Hammer <mhammer-at-midwest-dot-net>
|> To: tesla-at-pupman-dot-com
|> Subject: Rebuilding a neon
|>
|> I have acquired 3 Jefferson Electric 12kv 60 ma neon transformers
|> free of charge. One unit works fine and is working well on my coil.
|> I am trying to rebuild one of the dead units. I unpotted it ok and
|> once the tar was off it came to life. However there is some arcing
|> between the windings and core. So I have attempted to dismantle the
|> core and remove the windings. There are 4 rivets in the corners and
|> the windings are contained on a bar along one edge of the core.
|> Excuse my attempt at ascii artwork.
|>
|> _____________________________________________
|> | / \ |
|> | | SEC PRI SEC | |
|> | --\----- ------------------------/-- |
|> | | SEC |---| PRI |---| SEC | |
|> | | SEC | | PRI | | SEC | |
|> | | SEC | | PRI | | SEC | |
|> | | SEC | | PRI | | SEC | |
|> | | SEC | | PRI | | SEC | |
|> | --------| | --------| |-------- |
|> | |
|> | |
|> | |
|> |_____________________________________________|
|>
|> The bar containing the windings seems like it should slide
|> out of the rest of the core.But it seems quite unmovable.
|> Removing the rivets from the rest of the core didn't help.
|>
|> Also where are the magnetic shunts in this transformer. I don't
|> see anything that looks like a shunt plate.It just seems to be a 2 piece
|> core.
|>
|> I have rebuilt 2 Franceformer neons and they were a piece of cake.
|> This puppy has me stumped.
|>
|>
|> Mike Hammer
|> mhammer-at-midwest-dot-net
|
|
|Mike -
|
|
| Ahhhhhh. Brings back memories to me, as I have rebuilt MANY a
|Jefferson transformer. What you need to do is pry off the outer
|core laminations one at a time, taking care not to kink or bend
|any of them. It's a pain, but it's do-able.
|
| The sparks you see are most likely due to tar residue stuck in
|the space between the windings and the core. There are 'U' shaped
|pieces of mica which are *suppose* to prevent arcing, but...
|
| Once you get that 'bar' assembly off and cleaned up, replace the
|mica 'U' pieces with some HDPE plastic.
|
| The magnetic shunts are created by those two 'post' stubs reaching
|up from the bottom to the space between the HV secondary windings and
|the primary. Easiest way to reduce the leakage (and boost output) is
|to clip off every 8th or 10th 'stub' with a pair of snips. (Lightly
|tap out any edges with a hammer so that the cores stack neatly back
|together.
|
|BTW - You can increase the output current by placing *one* of the HV
|secondaries on 'backwards', and wire them in parallel. This will,
|however, cut the output voltage in half.
|
|
|- Brent
|