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2 wire secondary
Subject:
2 wire secondary
Date:
Sat, 12 Apr 1997 15:08:28 -0700
From:
Gary Weaver <gweaver-at-earthlink-dot-net>
To:
tesla-at-pupman-dot-com
I built a secondary coil using 2 wires side by side connected in
parallel. The wires are both #24 wound on a 4" PVC pipe 12"
long. I have another coil wound with 1 wire #24 on a 4" PVC pipe 12"
long. I tested the the performance of the 2 coils using
the same power supply, the same Richard Quick spark gap and the same .01
uf capacitor.
Primary is 1/4" copper tubing flat wound. 8 turns spaced 1/2" center to
center =.250 between the coils. The inside diameter
is 5.5" and the outside diameter is 13.5".
Secondary #1 is 532 turns of #24 wire 4.5" dia wound 11.5" long. Ohms =
14.519 KHZ = 596.8 uh = 10679
Secondary #2 is 2 coils 266 turns each of #24 wire 4.5" dia wound 11.5"
long connected in parallel. Ohms = 7.26 for one
coil divided by 2 = 3.63 for both coils. KHZ = 1193.6 for 1 coil. uh
= 2670 for 1 coil.
Test 1
Toroid 5"x9" on Sec. #1. Primary tap = turn 7. Output = thin blue 7"
sparks to a grounded sphere.
Toroid 5"x9" on Sec. #2. Primary tap = turn 1.75. Output = very white
hot 8.5" sparks to a grounded sphere.
Test2
Toroid 4.5"x16" on Sec #1. Primary doesn't have enough turns to tap.
Output = 0"
Toroid 4.5"x16" on Sec #2. Primary tap = turn 3.25. Output = very white
hot 12.5" sparks to a grounded sphere.
A coil wound with #20 wire 4.5" dia. 11.5" long, ohms = 3.767, KHZ =
935.7, uh = 4344. With toroid 4.5"x16" the primary
should tap about turn 4.5 unless I made a mistake in my calcualtions. A
difference of 1.25 turns in test 2.
The main advantage I see using 2 wires in parallel is the smaller
primary coil. Some of my primary coils are very large. Also
larger toroids can be used.
The 2 wire secondary coil output sparks are hotter and longer than the
coil wound with 1 wire. 2 #24 wires in parallel should
be about equal to a coil wound with #20 wire.
Gary Weaver Experement 7927