Original poster: "Steve Conner" <steve.conner@xxxxxxxxxxx>
>One may argue that our analysis is incorrect, but one
>cannot argue that the device is real.
Yes. That is all we are arguing, that your analysis is incorrect. I am quite
prepared to believe that your toroidal coils work fine, and now I have
studied your working a bit more, I can see why they might resonate at the
frequency you think they do. But I still maintain that it's not because of
"rope resonance" or whatever.
>Calculate the inductance from one half of one solenoid using L = u
>Nsqrd pi Rsqrd / l
>Set the wire length frequency to equal 1/ 2 pi sqrt ( LC )
>Substitute in L from above and solve for capacitance total. Subtract
>Medhurst's self capacitance and split this value between both ends of
>each solenoid
I think I see what you're doing now. You're loading the ends of the coil
with spheres or whatever, chosen to _make_ it resonate at the frequency that
the wire would if it were laid out straight and signals travelled in it at
the speed of light.
This will produce a working system, but I argue that the wire length
frequency is a total red herring. The only figures that are actually making
the answer "right" are the lumped inductance and the Medhurst capacitance.
You could load the coil to resonate at any frequency picked at random
(within reason) and it would probably work just as well. (try making the
spheres bigger on your toroidal coil and adding more primary turns- I bet
your coil works much the same)
>Take the speed
>of light at 3 x 10 to 8 m/s and divide this by the total wire length
>sum. This will give you the frequency for driving the tank circuit to
>get a full wave.
This is true only because you've loaded the secondary. It probably doesn't
resonate with a standing wave at this frequency.
As an experiment I took a solenoid coil and connected each end to one
terminal of my signal generator. I used an oscilloscope with a x100 probe
about 10" from the coil as an antenna to pick up any resonance signal.
The coil was 120mm diameter by 210mm long and had a 1570 turn single layer
winding of 0.125mm wire. That is 592 meters of wire. As I argued earlier, a
solenoid hooked up this way is electrically quite similar to a donut coil
with no loading capacitance added anywhere.
The first resonance I found was the half wave, with one voltage maximum in
the middle of the coil. This was at 422kHz.
The next one I found was the full wave (with two voltage maxima) and it was
at 652kHz.
(I checked the locations of voltage nodes by running a finger along the
winding. It detuned the resonance strongly when it was at a node, and not at
all when at an antinode.)
The frequencies for half and full standing waves in 592 meters of wire,
assuming the signal traverses it at the speed of light, are 253 and 507kHz.
Now by attaching a topload (middle load?) to the voltage node location, as
you do with the toroidal coils, I could surely pull the 422kHz resonance
down to 253kHz but really what would that prove?
>We have never advocated placing current nodes at the ends of
>solenoids for groundless systems, dont know where you got that from?
It follows logically from what you have posted in the past. Your toroidal
coils have a current node where the primary is. All I'm doing is cutting the
toroid at that point, straightening it into a solenoid, and driving the two
loose wire ends from a low impedance generator, so the current node is still
in the same place, topologically speaking.
Steve Conner