RE: PIRANHA-III Power control? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sun, 17 Dec 2006 01:27:26 -0500
From: Aron Koscho <kc5uto@xxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Subject: RE: PIRANHA-III  Power control? (fwd)

Terry,

A good starting point can be found here:
http://us.st.com/stonline/books/pdf/docs/3566.pdf


I have used this basic circuit with a MOT before for charging big caps
and it worked well. One problem that occurs to me right off is the peak
voltage out of such a circuit may still be high enough to cause
saturation issues (for a given cycle) with your MOTs. You could start
testing with a cheap hardware store 600W fan speed control. I have found
they can handle twice their rated current for short periods (cheap
components but TRIACs are tough).

Aron

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx] 
Sent: Sunday, December 17, 2006 1:04 AM
To: tesla@xxxxxxxxxx
Subject: PIRANHA-III Power control? (fwd)

Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sat, 16 Dec 2006 19:08:32 -0700
From: Terrell Fritz <terrellfone@xxxxxxxxxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: PIRANHA-III  Power control?

Hi,

I am working on PIRANHA III issues today.  A dual MOT system that runs
off 
a 120VAC 20A circuit with ease.  It is in the 8 foot arc to ground 
range...  About 2kW input at ~90% efficiency.

These coils like to run with the MOT input voltage at about 95-105 volts
to 
stay out of the MOT saturation range which just waists precious 
current.  Normally that is done with a 15 -20 amp variac...

http://drsstc.com/~piranha/PIRANHA/PIRANHA-3/PIRANHA-III-001.gif

Variacs are very nice, but they are real heavy and not real "modern" or 
solid state.  The charging circuit (MOT / Primary Cap loop) is resonant
too 
to drive up to a 15000 volt firing voltage...  But the waveforms are
pretty 
"tame" and the power factor is excellent without any fiddling.

http://drsstc.com/~piranha/PIRANHA/PIRANHA-3/PIRANHA-III-002.gif

It would be super cool to use a beefy lamp dimmer circuit or some
similar 
cheap but very reliable solid state thing to control power other than
the 
variac.  The PIRANHA input section is very forgiving of sloppy input
wave 
forms and all so no big deal there.  Ceiling fans are made for inductive

loads...

I don't know much about dimmer circuits and such so I can't guess at
what 
to do and feed the computer models well.  0:-|

If anyone knows what to do to make a cheap hardy dimmer type circuit
that 
could run two MOTs (~2kW)  I am all ears ;-))

Cheers,

	Terry