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neon xfrm

 * Original msg to: Nussbaum-at-silly-dot-com
 * Carbons sent to: usa-tesla-at-usa-dot-net

Quoting Ephraim Nussbaum <nussbaum-at-silly-dot-com>:

> I still can't figure out how to remove the windings. The 
> transformer was made by Jefferson Electric; did you by any 
> chance unpot one of these? The side view looks like this

     __----------------------------------__  |                    

     |  /                                   \ |
     | /                                     \|
     |/______________________________________\|_
     |   |  |          |  |           |  |    |
     |   |__|          |__|           |__|    |
     |________________________________________|_


> Around that inner core is the windings going through the 
> holes(looks like a house).

When you get this figured out you will most likely want to whack
your head a few times with a flat board :-)

The cores are assembled from two mating sections, much like a
tongue and groove construction used in furniture making. Where
the two sections are joined they are drilled through, from the
sides, and either a screw w/nut or a rivet is used for a fastener
to prevent the two sections from coming apart.

I am going to attempt to diagram this with ASCII art, but I am
not an artist, please bear with me:

      _____________________________________________
     |                                             |
     |                                             |
     |     -----------------------------------     | 
     |     |                                 |     |
     |     |     OPEN RECTANGLE IN CORE      |     |
     |     |                                 |     |
     |     -----------------------------------     |
     |            STAMPED IRON SHEET               |
     |_____________________________________________|


This diagram shows the assembled core without shunts or windings.
If you look carefully, there will be a fastener that is exposed
on the side of the core, even with the shunt plates and windings
installed. Look carefully.

      _____________________________________________
     |                                             |
     |  O            O           O             O   |
     |     -----------------------------------     | 
     |     |                                 |     |
     |     |     OPEN RECTANGLE IN CORE      |     |
     |     |                                 |     |
     |     -----------------------------------     |
     |  O            O           O             O   |
     |_____________________________________________|

The "O"s above mark _probable_ locations for the fasteners that
pin the two sections of the cores together. These locations would
be in the corners, or between the HV windings and the primary. Of
these locations only two holes will be actually drilled. My guess
would be that rivets are used through the holes in the particular
core you are looking at because I think you would have noticed
screws and nuts by now. 

      _____________________________________________
     |                                             |
     |  O <--Rivet Hole                            |
     |     -----------------------------------     | 
     |     |                                 |     |
     |     |     OPEN RECTANGLE IN CORE      |     |
     |     |                                 |     |
     |     -----------------------------------     |
     |                          Rivet Hole-->  O   |
     |_____________________________________________|


When you locate the fasteners, remove them. If the fastener is a
rivet you will have to block the core carefully with some pieces 
of wood and drill or grind the heads off before driving the
shafts out with a nail or small punch. Then separate the two
sections:

               ____________________________________________
      -----   |     |                                      |
     |  O  |  | O   |                                      |
     |-----|   ---------------------------------------     | 
     |     |                                         |     |
     |     |                                         |     |
     |     |                                         |     |
     |     ---------------------------------------   |-----|
     |                                       | O  |  |  O  |
     |_______________________________________|____|   ----- 


Once the core is apart, you can see how the windings are
removed/installed. The windings simply slide right off of the
ends of the "bars" of the disassembled core. I have also gone
ahead and detailed where the tongue and grooved sections of the
core are located; directly where the fasteners are installed.

I hope this helps, if you are still having difficulties with this
I can recommend a video tape produced Richard Hull that details
the overhaul/rebuild of a neon transformer. Explain your
difficulties in a letter to Richard Hull (he does not have an E-
Mail address) and he will be happy to write you back with the
information about one of his video tapes that details the
rebuilding of a neon sign transformer from beginning to end. 

You can contact Richard Hull at:

                 RICHARD HULL
             7103 HERMITAGE ROAD 
             RICHMOND  VA  23228 

His informational and educational videos are extremely detailed.
Though I have not personally seen his video on rebuilding neons,
it is my understanding that Mr. Hull has thoroughly covered
unpotting, disassembly, rebuilding, and testing of neon cores on
a two-hour SP recorded video tape. Given your difficulties, the
purchase of the video from Mr. Hull may be a wise investment. 


Richard Quick


... If all else fails... Throw another megavolt across it!
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