Re: Franceformer repair......

To: tesla-at-pupman-dot-com
Subject: Re: Franceformer repair......
From: gweaver <gweaver-at-earthlink-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Tue, 21 Dec 1999 11:29:44 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme
If the primary coil is bad it is not hard to rewind it.  If its like my neon
it will have 244 turns of wire on the primary coil.

You will have to use a meter to determine how many shunts to remove.  Be
sure to check one coil at a time and remove the same number of shunts from
each stack. A 60 ma neon should have 30 ma on each coil.  You can remove
enough shunts to get 50 ma from each coil and be totally safe.  Total output
will be 15K 100 ma.  NOTICE the location of the shunts are just as important
as the number of shunts.  Move the shunts back and forth between the primary
and secondary coil and you will see the meter ma amp reading go up and down.
Locate the shunts for maximum output between the 2 coil.  Then put something
between the coils and shunts to wedge the shunts in place so they will not
move.  

When I unpotted my neon I put several pieces of polyethylene between the
coils as the wedge.  I also put the same number of pieces of polyethylene
between the secondary coil and the metal transformer lamination to prevent
arcing.  I had 18 tiny pieces of poly in 8 places on both sides of the
secondary coils.

You can also put the unpotted neon in a plexaglass box or wooden polyester
coated box. Fill the box with high voltage oil to protect it from arcing.
Be sure to keep the transformer coils at least 1" from the box surface and
1" of oil covering the top of the coils.  I have a unpotted neon on my web
page if you want to take a look at it.  http://home.earthlink-dot-net/~gweaver

The oil protects the neon coils from arcing and also acts like the cooling
system.  

I got a 15K 30ma unpotted neon to put out 15K 72ma in HV oil.  I would not
try this with out using oil because the neon would probably self distruct.
I did this as a test just to see if it would work.  I didn't really care if
the neon burnt up because it was a test and I have 18 more neons.

Gary Weaver



At 12:04 PM 12/20/99 -0700, you wrote:
>Original Poster: Apollo <ollopa-at-jps-dot-net> 
>
>I got a nice little 15-60 Franceformer the other day to add to my
>NST collection, but there were a couple of problems with it.  It was
>only putting out 50ma of current, so the guy gave it to me for free.
>It looked like cleaning the heavy corrosion off the terminals was all it
>would need to be a-ok, but when I fired it up the lights flickered like mad
>and some smoke puffed out the lid.  I shut it off quick and checked it out
>with my ohm meter.  The primary and secondaries were looking good, but I 
>noticed that the primary winding is shorted to the ground, and thus
>connected to
>the secondaries.  Not a good condition!  I don't want to run it without a
>ground
>OR with the secondaries tied to the primary through the core.
>
>I've got the core out and about 98% unpotted.  There were four bolts (one
>in each
>corner) holding the core together.  I also noticed that the core seems to
>be made
>of two sideways U shaped parts with the seam going right down the middle
>(where the 
>primary winding is).  I've got the bolts out, but I can't figure out how to
>get the
>core apart.  Am I going to have to peel each layer of laminate off
>carefully, or should
>it pop apart with a screwdriver or two?
>
>Also, there are four banks of shunts (two per side).  How many shunts is it
>safe to 
>remove from each bank?
>
>Y.T. -
>Rick Richard
>
>
>
>