Re: NST current limit adjustment.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

A safer way is to put a low value resistor (say, 10 or 100 ohms) across the
NST output and then use your meter to measure the voltage across the
resistor.  30 mA through 100 ohms is 3 volts...

If you meter happens to come loose, or the fuse is bad, etc., at least it
won't fry...



Tesla list wrote:
> 
> Original poster: "Gregory Hunter by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>
> 
> You can measure the NST current with a regular analog
> or digital multimeter connected across the HV outputs
> & set on the amps function. I've done this many times.
> The meter will short the voltage down to nearly zero,
> and the meter can read the 30ma without harm. Make
> sure the DMM internal fuse is good. I had a blown DMM
> fuse one time and didn't know it. The fuse acted like
> a spark gap and my meter was fried! Also, use a cheap
> DMM just in case some thing goes wrong. Hook
> everything up, get yourself and your hands clear, plug
> in the NST from a safe distance away, and read your
> current measurement from the meter without touching
> anything. Unplug the NST. Make your shunt adjustments,
> repeat...
> 
> Greg
> 
> --- Tesla list <tesla-at-pupman-dot-com> wrote:
> > Original poster: "Rick W by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>"
> > <rickwilliams404-at-earthlink-dot-net>
> >
> > Hey all,
> >
> > I've depotted and reassembled my first NST. Replaced
> > the thick tar paper
> > wrapping with polypropylene .075" thick.
> > I noticed during dissassembly that some of the shunt
> > plates were out by half an
> > inch for current adjustment. I noted the position of
> > everything before
> > continuing the disaasembly.
> >
> > However, I don't believe everything can be within
> > calibration even after
> > reassembling everything exactly as it was.
> >
> > So my question is "how to readjust the current limit
> > shunt plates?".
> >
> > NST:
> > Franceformer 15K 30ma 450VA.
> >
> > Available equipment:
> > O-scope
> > Variac
> > Multimeter
> > Bunch of 50W resistors anywhere from .1 ohm to 50K
> > ohms.
> > A lot of assorted other parts.
> >
> > I have no high voltage probe though. If I need one I
> > can get one in about a
> > week.
> >
> > Thanks!!
> >
> > Rick Williams
> > Salt Lake City
> >
> >
> >
> >
> >
> >
> >
> 
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