Re: Measuring Dirver Current

>>From bigr-at-teleport-dot-comFri Jun 14 07:32:04 1996
>Date: Thu, 13 Jun 1996 22:10:35 -0700
>From: bigr <bigr-at-teleport-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: Measuring Dirver Current

>>> The transmission line current between the driver and resonator in
>>> a magnifier is of extreme interest to us, but again, no good plan
>>> has been devised due to the ultra high power of the arcs which
>>> might instantly vaporize any instrument used to measure it.  We're
>>> still thinkin' on this one.
>>Well the driver is closely coupled to the primary so I would think
>>that current at the earthed end should mirror that at the resonator
>>feedpoint. (Y-N)?

>Thermocouple type AC ammeters are available on surplus market and at
>hamfests, etc.  I've used these for measuring antenna current and they
>don't care how many KV of RF is applied.  However, you may need to put some
>extra bypass caps inside since God knows what might happen as Tesla coil is
>still different than 2KW CW RF.  Rob.

Malcolm, Rob, Richard Hull, All,

That's not a bad idea Rob.  Just to add to it a bit, you would not be able to get
a sample of the actual waveform or measure peak current at that point but you'd 
certainly get accurate averaged  RMS toaster watts. You could put a meter 
like this also between the top of the resonator (either a two coil or 
three coil system) and measure actual circulating current between the 
resonator and the topload.   If you enclosed the meter inside a thin aluminum
corona ball type shield with a hole in the side behind which would be buried
the meter, and viewed this meter remotely with a flashlight and telescope or
binoculars this would work just fine!  On a really big system you could install
an entire battery powered oscilloscope and current probe inside such a shield ball
with complete safety to the scope and again view remotely with 
binocs.  With this  you would see waveform too!  I've been thinking 
of this measurement idea for a while but haven't tried it yet. I 
don't have a coil system large enough that this data is of any real 
concern to me just yet.  Your post on this reminded me of it though.

Regards, rwstephens