Re: PIRANHA-III Power control? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

Moderated and approved by: Gerry Reynolds <greynolds@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sat, 23 Dec 2006 09:24:31 -0700
From: resonance <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: PIRANHA-III Power control? (fwd)



To keep the max current slightly below the 20 Amp trip that will trip most 
120 VAC single circuit breakers.  My dual MOT coil uses two separate 20 Amp 
circuit and each MOT will be adjusted to pull only 18 Amps at WOT.

We are testing both the 555 optoisolated system and also a phase shift 
system.  Whichever works best we will finalize into the printed circuit 
board.

Dr. Resonance


>>
>>At present we are working on a similar circuit to eliminate variacs.
>>
>>We plan on using a series choke with the MOT primary.
>
> Why???  I leave the shunts in, so the max current is about 25 amps in any
> case.  A MOT is one heck of a shunt already!!!  Why add another shunt to a
> BIG existing shunt? ;-)))
>
>>We are winding up
>>some 2 inch ID x 18 inch long PVC pipe filled with cut 1/8th inch dia. 
>>steel
>>rods to add a small inductance to clip off the harshest peaks on the 
>>inrush
>>current.
>
> Sound's big and heavy...  Perhaps your circuit is different, but such an
> inductor seems like a waist to me.  PIRANHA has no big inrush
> current....  It might ring and kick back ;-))  but that's what big a**
> snubbers are for ;-))
>
>>We plan on using one in each MOT primary.
>
> Two of them!! :-|
>
>>Unlike Terry's circuit,
>>we our using a single MOT running around 16-18 Amps each running off a
>>separate 120 VAC circuit
>
> You meant "two MOTs total"...  Each run from different legs of the 120VAC
> to a site for "trick" 240 VAC access...  Lots of lights and "flip this 
> plug
> stuff".
>
>>  --- shooting for a 4.0 to 4.4 kVA total input into
>>the system.  We are shooting fgor 7-7.5 ft long sparks on a portable coil
>>that can run on two separate 120 VAC circuits and not require 220 volts 
>>for
>>portable operation at schools, etc.
>
> At that power you should get 9 feet form the "standard" Freau equation,
> "let alone" anything with a solid state gap.  Most "schools" will not
> "tolerate" anything with more than a "tiny" 2 foot (PIRANHA-I) spark 
> length
> ;-))  But maybe you know the "better" schools ;-))
>
> I assume you are using BIG industrial MOTS for that power...  Easy to buy
> them from here:
>
> http://www.amiparts.com/
>
> PIRANHA can be changed to use the full AC line voltage as is, but the MOT
> saturation "waists" power then :-p  Variacs are not "THAT" bad at "this
> level", but if a "simple" little circuit could get rid of the variac while
> preserving the low MOT saturation, it would be sweet ;-))
>
> I am now thinking of just making the PIRANHA do it
> "automatically"  *;-))  But such things are shrouded in mystical secrecy 
> :o)))
>
>
>>Brian V. is working together with us on this project.  I also want to
>>eliminate the necessity of using heavy variacs for current control.
>
> "voltage kills", not "current".  I'll probably still have contactors and
> breakers, so the cost / weight is not a giant issue really....  All though
> PIRANHA is cheap for "solid state", it still is not "cheap" compared to
> conventional...
>
>
>>This posted opto-isolated circuit might prove to be the best answer as it 
>>is
>>totally independent of the AC line for triggering.
>>
>>I will advise on how it works out.
>
> I thought you were thinking of a circuit like mine.  But yours seems very
> different ;-)))  Maybe in the endzone, the "best" will be a "combination"
> of the two :-)))
>
> Cheers,
>
>         Terry
>
>
>
>>Dr. Resonance
>>
>>
>> >
>> > Here is a "A High-Resolution Digital Dimmer" based on the 555 timer. 
>> > It
>> > looks very nice.  I'm inspired!
>> >................
>
>
>
>