Inside A Neon

To: tesla-at-pupman-dot-com
Subject: Inside A Neon
From: Tesla List <mod1-at-pupman-dot-com>
Date: Sun, 12 Oct 1997 22:01:42 -0600 (MDT)
Approved: mod1-at-poodle.pupman-dot-com



---------- Forwarded message ----------
Date: Mon, 13 Oct 1997 10:52:23 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: tesla-at-pupman-dot-com
Subject: Inside A Neon

Hello All,
            I finished recovering the core from my partially dead 
neon. A few observations:

- Insulation on the primary wire was not wonderful and peeled off 
when stuck to the tar. However, it was just fine for the primary 
voltages.
- they used a thick layer of mica between the top of the secondaries 
and the core.
- I don't think the secondary wire insulation was all that great. 
There was clear discolouring of the wire in the centre of both 
windings and I am guess that this is what failed. Wire thickness 
seems just fine for 60mA *provided* it has sufficient cooling and I 
don't think the way these things are built that the cooling is good 
enough.
- the secondary windings were not varnished and I think this was a 
major contributor to the failure. I have wound a number of ferrite 
cored transformers whose peak voltages hit 20kV on very much smaller
cores and I have never had a failure. Also far fewer layers than 
those in this thing.
- the core of this transformer does use E-I lams. Cutting the centre-
leg out to make a C-I core would halve the pole area which would 
require about twice the original primary turns to keep core flux 
density below saturation (4 x L).

FWIW,
Malcolm