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THOR resonance freq. measurement results
Hello all (again).
I have also been measuring the primary and secondary resonance frequencies
and I
would like somebody to comment my results.
Secondary measurement
--------------------------------------
I disconnected the secondary bottom from ground and connected the function
generator hot lead to it. Func. generator cold lead heartened. Measuring the
electric field with a scope probe. Setup using long shielded cable to saty far
from the coil. Top toroid included in the measurement..
I measured 3 resonance frequencies:
65.46 kHz
222.75 kHz
346.3 kHz
Can somebody explain the error (these are not exactly 1st, 3th and 5th
harmonics, why?) ?
I also measured the frequencies were the measured field amplitude was halved:
65.72 kHz halved
65.46 kHz full
65.21 kHz halved
But I don't recall how to calculate Q from it. Could anybody help, please?
Primary measurement
---------------------------------
First I tried to measure primary inductor and capacitor connected as a series
resonator, but I could only and always spot the secondary res. freq. Then I
connected them as a parallel resonator, fed them with the function generator
through a 0.1 ohm resistor and measured the resistor voltage (i.e. the current
sourced). I wrote down the points were the current was MINIMUM.
Primary turns Freq. Wintesla predicted
used (kHz) (kHz)
9 54 54
8 60 61
7 66 (78) 70
6 70 81 81
(there was little difference between 70 kHz and 81 kHz minimum levels)
5 (72) 96 96
The numbers in brackets are a second minimum that was not so low in value
as the
first one. Below 5 turns it was very hard to detect the minimums, so I gave up.
I am anyway interested only in frequencies near 65 kHz. It seems to me that
with
the aid of the Wintesla prediction it is easier to read the measurement results
and to conclude that the prediction was correct. Any comments anybody?