Multiple secondary coils

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: gary350@xxxxxxxxxxxxx 


Several years ago I did some experements and posted the results 
here.  Not sure if anyone remembers.  I thought maybe I would post 
this again to refresh everyones memory.

I built 3 secondary coils exactly identical only difference was, #1 
coil had 1 layer of #24 enamel coater copper wire 950 turns, #2 coil 
was identical but it has another coil would over the 1st coil both 
coils were connected in parallel.   #3 coil was the same as the 
others 950 turns #24 wire, another 950 turns #24 wire wound over it, 
and another 950 turns #24 wire wound over it too.  All 3 coils 
connected in parallel.   Output from Coil #2 was much better than 
coil #1 it was noticably better output discharge sparks were much 
longrer nothing else in the circuit had been changed just the 
secondary coil.    Output from Coil #3 was longer than coil #2 it was 
hard to see how much longer the sparks were without actually 
measuring the length of the sparks.

I built a tesla coil with 3 secondary coils in parallel.  All 3 coils 
were wound on 4" PVC pipe with 950 turns of #24 wire.   This tesla 
coil was compaired to an identical tesla coil with only 1 secondary 
coil.   The TC with 1 secondary coil had a flat wound primary 20 
turns of 1/4" copper tubing.   Distance between the inside turn of 
the primary coil and the secondary was 2".   The primary coil on the 
TC with 3 secondary coils had to be made larger in diameter the 
distance from the inside turn of the primary coil was 2" to the 
secondary just like the other TC.   Input power was the same, cap was 
the same, spark gap was the same, top load was the same, output 
sparks were a little bit longer.   Interesting thing was the TC with 
3 primary coils connected in parallel produced output sparks just 
about equal to the TC with 1 secondary coil with 3 winds all would 
over each other and connected in parallel.

I wound 3 secondary coils on 4" PVC pipe all 3 coils were wound with 
#20 enamel coated copper wire 950 turns each coil.   I also would 
another secondary coil on 10" PVC pipe #20 wire 950 turns.    I built 
a primary coil for each system.  I used the same cap, same spark gap, 
same top load.  The output on the TC with 3 secondary coils in 
parallel was a little better than the coil with just 1 secondary 
coil.   I am getting streamers 138" long on the 10" secondary coil 
and streamers 144" long on the 3 secondary coils in parallel.

It is not necessary to have a large PVC pipe to wind a large diameter 
secondary coil if you are building a large TC.  You can accomplish 
the same thing by putting several smaller diameter secondary coils in 
parallel.

3 to 1 ratio diameter to length is the best.  3 to 1 is better than 4 
to 1 and 4 to 1 is better than 5 to 1.  I built 3 different TCs each 
secondary coil wound with #24 enamel coated copper wire 950 
turns.  Coil #1 was wound on 4" PVC.  Coil #2 was wound on 6" 
PVC.  Coil #3 was wound on 8" PVC.  Everything in each TC circuit was 
the same, power supply, spark gap, caps, topload.  Output sparks on 
the 6" coil were noticablly better than the 4" coil.  Output on the 
8" coil was better than the 6" coil but not a lot better.

If I can find all my notes I could include things like the exact 
length of each output spark, information about streamers, 
etc.   Someone may have this info saved somewhere.   That was 5 years 
ago maybe longer I am not sure where my notes are.  This was way back 
in the days before the electronic cameras.  Too bad I didn't take 
more pictures.  All the pics I posted years ago were taken on my old 
Nikon.  The photos were scanned.

Gary Weaver