Re: Multiple toroid capacity

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

Original poster: "Dr. Resonance by way of Terry Fritz <teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>


Scott

--snip--

We placed the toroids atop a large stack of cardboard boxes to the exact
same height above our concrete shop floor that they would be when placed
atop the sec. coil.  Also tried it on the sec. and result was same
measurements.

DC

 > Dr. Resonance -
 >
 > When you directly measured the effective capacitance of a topload using a
 > Wavetek LCR meter, can you describe the test setup you used? Was the
toroid
 > suspended in free air at operating height, or mounted on the secondary?
How
 > was the LCR meter connected to the toroid? Was a ground plane used in the
 > test setup?
 >
 > I'm interested in your method of directly measuring toroid capacitance as
 > previous searches for a measurement method yielded only "indirect" means
 > (measure resonant frequency of bare secondary, add topload, again measure
 > resonant frequency and derive the topload capacitance from change in
 > frequency).
 >
 > A simple, reliable, accurate means of directly measuring toroid
capacitance
 > would be useful, especially for odd-shaped or "compound" toploads
consisting
 > of stacked toroids, corona ring plus a sphere, etc.
 >
 > Regards,
 > Scott Hanson
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Sunday, April 13, 2003 11:39 AM
 > Subject: Re: Multiple toroid capacity
 >
 >
 >  > Original poster: "Dr. Resonance by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>
 >  >
 >  >
 >  > Due to the "shielding effect" when multiple toroids are used the value
is
 >  > always less than the value of two separated individual toroids added
 >  > together.  With two toroids a rule of thumb is you deduct from the
total
 >  > separate added capacitance approx. 50% of the value of a single
toroid's
 >  > capacitance.  This will give you a good ballpark figure assuming both
 >  > toroids have the same physical size.
 >  >
 >  > If the sizes are different then it's usually easy just to measure the
 > total
 >  > with a Wavetek or equiv. meter.
 >  >
 >  > Dr. Resonance
 >  >
 >  > Resonance Research Corporation
 >  > E11870 Shadylane Rd.
 >  > Baraboo   WI   53913
 >  >
 >  >  > When running stacked toroids on a coil, how is the total combined
 >  >  > capacity of them calculated?  Surely it isn't as easy as adding
 >  >  > together the individual capacities...or is it?
 >  >
 >  >