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Subject: 10KV RMS -at- 300MA

Subject:     Subject: 10KV RMS -at- 300MA
       Date: Sun, 04 May 1997 20:34:12 -0700
       From: kip Greiner <sgreiner-at-wwnet-dot-com>
Organization: 
        . To: tesla list <tesla-at-pupman-dot-com>


Hi All but especially owners of the subject xformers

This is a preliminary report on first sparks using a pair of these
transformers with the secondaries series connected for 10kv output and
the primaries connected in anti parallel.

I wound a secondary on an old wooden skeleton frame which is 12" x 30".
I used insulated #22 stranded wire (7/30) which is .050" OD giving 600
turns. The design frequency is about 130khz. I used an old primary which
is solenoidal wound with .375" tubing with .25" spacing. The diameter is
18". The measured Q of this secondary is over 600.

I used my standard synchronous rotary gap with just 2 operating gaps due
to the low voltage running at 1800rpm and giving 1 firing per 1/2 cycle
of the mains. The gaps perform very well. There is no roughness or
misfirings. 

I use 1 safety gap across both xformers set at 10kv  and individual
safety gaps across each xformer which are set for 5kv. The gaps do not
fire during operation.

The transformers deliver 10kv total open circuit with a primary cap of
.08 and no caps in the resonator winding. The secondary was placed about
1" above the top turn of the primary (the exact coupling is yet to be
determined). A 5.5" x 27" toroid was used as a first try.

After adjusting the primary tap from 5 turns to 6 turns the discharges
exceed 54" point to point. This is excellent as a first pass.

I have not measured the power input yet but it looks as if I am not
fully stressing the transformers at all. The voltage across the output
of the xformers during operation falls to 8kv. This may be due to a need
for a phasing adjustment of the gaps or the primary cap may have to be
adjusted.

I let her rip for a full 5 minutes with no further adjustment putting
out 54" discharges. Nothing even got warm.

I think we have a winner with these transformers. I was leaning on them
pretty hard with no apparent ill effects. Of course a lot more testing
and tuning needs to be done, but I think 2 of these things may be able
to get to 6" discharges which is my goal.

Damn the torpedos....full speed ahead. More reports will follow.

Skip