Re: Cold Cathode Transformer

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>

Cold cathode transformers are very probably current limited the same 
as NSTs. The reasoning behind this is that we know gas discharge 
tubes only work on a current limited supply. Without ballasting they 
just explode.

If you're in any doubt, you could connect a milliammeter across the 
HV output bushings (essentially shorting it through the meter) and 
ramp up the input voltage using a variac. You should see that the 
meter reads about the nameplate current rating - 120mA in your case - 
when you apply the full 120V to the primary. This is a somewhat more 
gentle test than just drawing arcs off it to see what happens.

Make sure your meter can safely carry more than 120mA. If the fuse 
blows, the  full 15kV will appear across it and the whole meter will 
more than likely go to a fiery grave from internal arcing. For the 
same reason, don't touch the meter - and especially don't move the 
range switch - while the test is in progress.

Steve Conner
http://www.scopeboy.com/
"When a man is tired of Tesla coils, he is tired of life"

Tesla list <tesla@xxxxxxxxxx> wrote:
Original poster: "C. Sibley"

I have the good fortune of recently purchasing a
15000V, 120mA "Cold Cathode" transformer made my
Transco.

The gentleman that I bought it from told me that Cold
Cathode transformes are not current limited.