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Re: electronic transformers
If you mentioned the ones from Neon tech, San Diego, CA, here my experiences:
I bought some R12-S (running on 12VDC, giving abt. 20mA @ 1200 Volts),
very expensive to get them to Germany, but they were smalles for neat art stuff.
They ( NeonTech ) guarantee for driving up to 8 feet of 12mm Ar/Hg, but it's
not delivering as much.
It's absolutely sensitive on too long tubes (tries to run 0.7m of 6mm Hg
tubing) - with a burnout rate of nearly 30% after 2-3 hours.
Never try clear red - it will blow up immediately, independent on the tube
length and ignition voltage.
Why does this happen: I dismanteled one unit after burnout by crushing
the epoxy resin in liquid nitrogen (i'm student of low temp physics
at Duisburg University). What i found was a winding to winding short in the
secondary of the little transfo, the used NO insulation between the layers
of wound wire. This let the driver MOSFET fail, causing a short in the 12V
DC circurit (-- imagine what happened, my 12DC supply delivers 60 Amps
continous).
This failure might be caused by the straight forward design of the driver:
there is NO feedback from the output to the driver, so nothing regulates the
power put into the transfo depending on the power consumed by the tube.
This results in the bad characteristics ( so no clear red can be used)
and in the extreme sensitivity against open output leads or too mucht tubing.
Another case happens at low input voltage: don't try to run the RS12-S at
voltages lower than 12V. It will start parasitic oscillation causing the
MOSFET to run hot (swallowing more than 600mA) and immediate burnout.
The tube gets darker, but the power input goes up at lower voltage put in.
- Just cheap design.
Someone with similar experiences?
Marcus Thielen,
University of Duisburg, Germany
Student in the lab for low temperature physics.
Doing Neon art as pure amateur in my parents garage with all equipment
homemade.
References: