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Re: Top 1/3
From: Mark S. Rzeszotarski, Ph.D.[SMTP:msr7-at-po.cwru.edu]
Sent: Thursday, September 04, 1997 7:36 AM
To: Tesla List
Subject: Re: Top 1/3
Hello All,
George W. Ensley said:
>Malcolms puzzle got me thinking about the behavior
>of a conventional TC's secondary coil. I was wondering
>if it truly does act as a 1/4 wave transformer with a
>nice smooth transformation from bottom to top. or
>Could the ratio be somewhat misshapen by the effects
>of coupling from the primary or a top load that is not
>sized correctly.
There is a simple method for taking a look at this visually if you
can operate your coil without spark breakout. Tape about 20 NE-2 neon bulbs
to a plastic rod, spacing them about 1 inch apart. Short the turns of each
individual bulb by twisting the leads together, but insulate the connections
between the bulbs. You now have a poor man's electric field wand which you
can move around a tesla coil operating at low power levels. The neon gas
ionizes and turns on around 90 volts or so. If you do this next to a well
tuned tesla coil and slowly ramp up your power supply using a variac you
will observe the quarter cycle voltage standing wave you expect. The bulbs
will light from the top of the secondary on down as the voltage is ramped
up. The toroid on top will alter the field distribution somewhat
(desireable), and you will get some extraneous fields from the vicinity of
the primary. My probe cost about $3.00 to construct, taking into account
the 10 cent each NE-2's, electrical tape and the plastic wand. It is well
worth the investment, and can survive spark breakout unlike some of my other
test equipment.
Regards,
Mark S. Rzeszotarski, Ph.D.