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NEON/SHUNTS(NEED HELP!!)




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From:  Zuma [SMTP:mwise-at-ns.sosis-dot-com]
Sent:  Saturday, January 31, 1998 10:53 PM
To:  Tesla List
Subject:  Re: NEON/SHUNTS(NEED HELP!!)

> > Chris,
> >
> > Removing shunts allows more primary magnetic flux to engauge the
> > secondary, increasing the secondary's short circuit current. Since
> > there's no free lunch (on Chip's List as least :^)), this also increases
> > the amount of primary current drawn. A shorted primary would most likely
> > cause severe overheating or your line circuit breaker to pop.
> >
> > If you want to measure your tranny's new short circuit current,
> > CAREFULLY connect a 100 ohm 1 watt resistor directly across your
> > transformer's output bushings and measure the output voltage developed
> > across the resistor with a cheap battery-powered VOM or DVM. Hook
> > everything up solidly, and ramp the power up with a variac... and STAY
> > AWAY from all of the HV side wiring and the meter while making the
> > measurement. Look for any signs of arcing while ramping up the voltage,
> > and fix the problem. Set the variac to output 120 VAC.
> >
> > The low valued resistor will force the transformer to go current
> > limiting mode, and the AC RMS voltage you measure will allow you to
> > measure the value. Let's assume you measure 8.5 volts:
> >
> >    Ineon = V/R = 8.5/100 = 85 mA
> >
> > This approach also comes in very handy when you get "warranty return"
> > transformers, since these often have missing faceplates - the faceplates
> > are often removed and sent back to the neon sign equipment distributor
> > for credit, saving the hassle of sending back a big pile of 40 pound
> > doorstops.
> >
> > Hope this helps, and safe coilin' to you, Chris!
> >
> > -- Bert --

 I have a question concerning this. I tried this and according to the
 meter it was reading a max of 6.0 volts. Does that seem right? I used
 the same size of resistor you suggested to come up with this 6.0v.
 I also wanted to ask if not running full 120volts through the primary
 affect the ma on the secondaries? The plug I used is running at has
 a fluxuating voltage of 113-115volts according to the meter. Could this
 be why I am not even getting more than 60ma out of my tranny? Remember
 I removed 2 shunts from each of the sets of 23, so my line of thinking
 says I should have increased the ma at least a little. But no such 
luck.
 do you think removing more would help or would that possibly destroy
 my primary or even the whole transformer?
 
 Thanks
 Chris