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Subject: Re: My new coil
>Welcome back Julian!
>
Thanks Jim its good to be back. While I've been away
apart from building a new coil I also had my house
re-built! It now has a double garage for my TC -
the car can stay outside.
>Try this: Connect your resistive ballast to your pig's primary. The
>pig's secondary to your cap and rotary. (all in parallel) Leave your
>TC elsewhere. I was able to cause my rotary to flame a complete circle
>using this ballast test! This shows 2 failures: bad quenching in the
>rotary gap and not enough inductance in the ballast. As soon as I put
>in 9mH of inductance (home wound) into my pig's primary circuit, the
>rotary flame stopped and was replaced by a very loud, smooth spark!
What about the chokes in the primary circuit? Won't they perform as
balast also? If I wound larger chokes would they function as balast
as well as filtering the RF? Or is it just easier to wind large chokes
for a low voltage circuit?
>Next time add a "BLAST" shield to protect you from flying debris and
>try your rotary out without any HV applied.
I did at full power - no problems! I concluded that the shock waves
produced by the sparks in the gap caused the vibrations.
>>4) Connect second pole transformer (5KVA)
>
>Halt! before you add another pig,
>
> (you can run your 5kVA unit up to 10kVA or 15kVA for short
> times {several 10s of minutes is a short time for a pig:)
Yes I know, but its output will still be 11KV. From reading other
messages on this list many people are running their coils on 15KV or
more. I can not achieve this without the second pig. I am worried
that my caps will fail with higher voltage. They use 4x10mill poly
sheets between the plates in oil. Will they blow?
>tweak all the other parameters in your system and add some inductive
>ballast in your pig's primary circuit. The inductive spike that
>occurs in this ballast, when the spark gap quenches, will help charge
>your TC's primary cap faster resulting in much longer arcs. When you
>add inductive ballast to the primary circuit you must also add some
>PFC caps or Motor start caps across the line to prevent this inductive
>spike from traveling into your house mains and blowing things. (like
>the RFI filters between it and the house mains;)
Thanks for the info, I had always assumed that inductive balast was
just there for current limiting. I have some PFC caps from flourescent
tube fittings 8uF at 250VAC they should do the trick!
Also
>Wow, I'm sorry for your rotor breaking, but you were getting 4-5'
4' to a fixed point - I measured it. It does have a toroid,
but it is the same diameter as the coil - I suppose you could
call it a lid.
>withoug a toroid?!? Amazing. Got any photos of this?
>
>You got alot you are adding, have fun, and protect yourself (Mainly from
>the flying rotors ;).
>
>I'm currious if you have a safety gap (Well, I'm sure you do), and did
>it fire like crazy when your rotor broke? Did this melt down the safety
>gap or did you catch it quick?
>
>I gotta see this, next run, please please grap some pictures!!
>
>Jeremy Bair
I think its time to put my rotary in a box, although I'm having lots
of fun with it sat on the bench. I melted the stationary electrodes
the last time I fired her up. The electrodes are made of mild steel
which makes the gap look like a firework when melt down occues. Time
to get some tungsten I think, although steel is cheeper.
I am working on getting some pictures done, although this weekend is
already booked solid with video tape editing. When I get some time
I will film the coil running and grab the best frames.
Safety gap, what safety gap? The darn thing kept flashing over
during setup, so I increased the gap. The problem I have here
is that once an arc establishes its self it draws so much current
that the fuse blows. (the arc looks more like a flame, and is
very hot.) The gap is now too wide for it to be any good I
think, altough I have noticed it firing occationally when coil
running at full power - this puzzles me, why dont I get the flame
like arc as before (need better RF chokes, and more fuses).
The gap is too wide to allow arc over from direct voltage
of the pig.
Pictures will follow... eventually
Julian Green.