Long Lost Transformer Thread

Hi all,

Firstly I must apologise for not replying sooner but I am now able to.

I had aquired some unidentified transformers that at first glance
looked like neons except they only produced 900 V.

When I first tested them, I didn't even think of the autotransformer
possability and I thought they were shorted down. Yet they still drove
a load ok - time to call for help and I wrote to the list asking if
any one knew anything about them.

Then a series of mail server problems and a work dead line prevented
me from following up promptly.

Over that time, I got them completely unpotted and they look like this,

  brown     o>|||
              |||  17 Ohm
              |||  240 V
  blue      o>|||----------|||
              |||          ||| 350 Ohm
              |||  350 Ohm ||| 800 V
              |||  800 V   |||
              |||          |||
 ceramic    o>|||.        .|||<o ceramic terminal.

So I unsoldered all the wiring, rephased the secondaries and I
now have a transformer that puts out 1600 V no load and 1400 V
at 75 - 80 mA. Woooho! I wish I had about 6 of them. The last
traces of tar were very hard, brittle and conductive - only
several hundred ohms but conductive - I'd say the core got
so hot that it coked the tar!

Glenn Baddeley was able to supply me with a manufacturer's part
number since he had looked at a transformer from the same source
some time ago that had a part number on it. I got in touch with
the manufacturer this morning.

They are for running 6 foot long T8 type fluorescent tubes.
They have no filaments and were used on rail ways for lighting,
where the continual vibration lead to short filament lives. The
transformer design dates back to the late 20's. He has 30 year
old tubes that are still running. But the tubes are hand made
and expensive now days.

Thanks for reading,

Nick B.