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Hi All -
Paul has my specs, but thought I should send for all. Paul, Fr has
changed due to measurement technique.
Let me first describe the setup:
Base contains MMC and Gap. 10 inches up is the flat primary coil
supported on pvc stand. In the center of the primary is a pvc tube which
supports the secondary flat coil. The secondary plane is perfectly
horizonatal with the
primary's plane. The secondary has a brass threaded rod 12" extending up
from the secondary ~11.75" with a 1" solid brass sphere on top.
Here are dimensions:
All measurements in inches.
Secondary Flat Coil:
298 turns
0.0225 total wire diameter (0.0201 bare).
13.9775 outer diameter.
0.625 inner diameter.
13.9 ohms (checked with 2 meters)
11.9 mH
Primary:
4.2 turns
14.125 outer diameter
10.25 inner diameter
9.3 uH (via Acmi - meter can't go that low)
0.25 wire size (copper tubing)
0.271 average spacing (edge to edge)
MMC measures 25nF.
Secondary is 5.125 inches above primary all around.
Found the following applying signal to the base of the secondary with
primary in position. The scope probe used a 2" strait wire as antenna.
Placement was tried a few feet above coil, but noise is horrible.
Placing the probe couple feet away and horizontal to the plane of the
secondary provided clean enough signals.
(values are kHz):
74.1
111.1
146.3
293 Fr
435 (can't sweep to next resonance - out of range)
Meter can't read capacitance directly. Using the Fr of 293kHz, C =
24.8pF.
If I measure Fr directly connecting the probe to the secondary terminal,
I read 330kHz, then C = 19.5pF.
For Q = Fr/(Fhi-Flo), I positioned Fr at 5 squares, and adjusted to 3.5
squares above and below Fr.
Fhi=296kHz, Flo=286kHz, Fr=293kHz, Q=29.3 (not sure what to make of
this). I tried the probe above about 4 feet and get the same.
Measured mutual inductance using 2 meters side by side for concentric
readings:
10.53A primary current
232mV secondary volts
Measured prior to running Acmi: M=58.44, K=0.1749
ACMI says:
SCNY.L| SCNY.R| PRMY.L| PRMY.R
12.01 mH| 14.84| 9.30 uH| 0.00
SCNY-PRMY.M|SCNY-PRMY.K
59.00 uH| 0.1765
Thats all for now. Acmi input file is below.
Take care,
Bart
; Bart Anderson's Flat Spiral Secondary.
units inches
secondary {
radius1 0.3125 ; Inner turn radius
radius2 6.98875 ; Outer turn radius
height1 0.0 ; leave at 0 for flat coil
height2 0.0 ; leave at 0 for flat coil
conductor 0.01005 ; bare wire radius
turns 298 ; number of turns
}
primary {
radius1 5.125 ; inner radius
radius2 7.0632 ; outer radius
height1 -5.125 ; inner turn height
height2 -5.125 ; outer turn height
conductor 0.125 ; bare wire radius
turns 4.2 ; number of turns
}
--Boundary_(ID_JyDqUG4fIXTujgLBb/B4XQ)
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Hi All -
Paul has my specs, but thought I should send for all. Paul, Fr has
changed due to measurement technique.
Let me first describe the setup:
Base contains MMC and Gap. 10 inches up is the flat primary coil
supported on pvc stand. In the center of the primary is a pvc tube which
supports the secondary flat coil. The secondary plane is perfectly horizonatal
with the
primary's plane. The secondary has a brass threaded rod 12" extending
up
from the secondary ~11.75" with a 1" solid brass sphere on top.
Here are dimensions:
All measurements in inches.
Secondary Flat Coil:
298 turns
0.0225 total wire diameter (0.0201 bare).
13.9775 outer diameter.
0.625 inner diameter.
13.9 ohms (checked with 2 meters)
11.9 mH
Primary:
4.2 turns
14.125 outer diameter
10.25 inner diameter
9.3 uH (via Acmi - meter can't go that low)
0.25 wire size (copper tubing)
0.271 average spacing (edge to edge)
MMC measures 25nF.
Secondary is 5.125 inches above primary all around.
Found the following applying signal to the base of the secondary
with primary in position. The scope probe used a 2" strait wire as antenna.
Placement was tried a few feet above coil, but noise is horrible. Placing
the probe couple feet away and horizontal to the plane of the secondary
provided clean enough signals.
(values are kHz):
74.1
111.1
146.3
293 Fr
435 (can't sweep to next resonance - out of range)
Meter can't read capacitance directly. Using the Fr of 293kHz, C
= 24.8pF.
If I measure Fr directly connecting the probe to the secondary
terminal, I read 330kHz, then C = 19.5pF.
For Q = Fr/(Fhi-Flo), I positioned Fr at 5 squares, and adjusted
to 3.5 squares above and below Fr.
Fhi=296kHz, Flo=286kHz, Fr=293kHz, Q=29.3 (not sure what to make
of this). I tried the probe above about 4 feet and get the same.
Measured mutual inductance using 2 meters side by side for concentric
readings:
10.53A primary current
232mV secondary volts
Measured prior to running Acmi: M=58.44, K=0.1749
ACMI says:
SCNY.L| SCNY.R| PRMY.L| PRMY.R
12.01 mH| 14.84| 9.30 uH| 0.00
SCNY-PRMY.M|SCNY-PRMY.K
59.00 uH| 0.1765
Thats all for now. Acmi input file is below.
Take care,
Bart
; Bart Anderson's Flat Spiral Secondary.
units inches
secondary {
radius1 0.3125 ; Inner
turn radius
radius2 6.98875 ; Outer turn
radius
height1 0.0 ; leave at 0 for flat coil
height2 0.0 ; leave at 0 for flat coil
conductor 0.01005 ; bare wire radius
turns 298 ; number of turns
}
primary {
radius1 5.125
; inner radius
radius2 7.0632
; outer radius
height1 -5.125 ; inner turn
height
height2 -5.125 ; outer turn
height
conductor 0.125 ; bare
wire radius
turns 4.2 ; number of turns
}
--Boundary_(ID_JyDqUG4fIXTujgLBb/B4XQ)--
--------------E38243EA9D309BC60258E766--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.