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Re: 15kva 14.4 kV Transformer.. (fwd)



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



---------- Forwarded message ----------
Date: Fri, 22 Dec 2006 21:39:00 -0700
From: resonance <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: 15kva 14.4 kV Transformer.. (fwd)




I'm beginning to think that due to the higher efficiency of IGBT switching 
(output sparks are much hotter) that the pri currents are higher and much 
harsher on the MMCs than a typical spark gap switched cap bank.  Less losses 
equals more current in the pri and higher stress on the MMCs.

I don't have hard data to support my theory --- just a hunch.

Dr. Resonance


>
> Excellent DC!
>
> I find that my MMC eventually fails (before the IGBTs provided no
> "special events" occur).  I have one DRSSTC that has gone through 2
> MMC banks now, but still has the same IGBT set.  It consistently pumps
> out 6 foot sparks at 1300W input.  If given the chance, id also try
> running one of my coils for extended periods of time to find out where
> the bottleneck in the design is.
>
> Steve Ward
>
> On 12/22/06, Tesla list <tesla@xxxxxxxxxx> wrote:
>> Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx>
>>
>>
>>
>> ---------- Forwarded message ----------
>> Date: Thu, 21 Dec 2006 21:54:16 -0700
>> From: resonance <resonance@xxxxxxxxxxxx>
>> To: Tesla list <tesla@xxxxxxxxxx>
>> Subject: Re: 15kva 14.4 kV Transformer.. (fwd)
>>
>>
>>
>> The same coil you saw at the open house, the 24 inch dia one.   It should
>> run up to 16 ft when we get the right driver on it.  We didn't push it 
>> very
>> much --- wanted to see how the coil would hold up for a possible nearly
>> continuous application.
>>
>> IGBTs were the PowerEx series, 1,000 Volt, 1,200 Amp if I recall right. 
>> I
>> can't look at the box due to the fact I'm a long way from the shop right
>> now.
>>
>> Dr. Resonance
>>
>>
>> >
>> > ---------- Forwarded message ----------
>> > Date: Thu, 21 Dec 2006 14:39:35 -0600
>> > From: Terry Blake <tb3@xxxxxxx>
>> > To: Tesla list <tesla@xxxxxxxxxx>
>> > Subject: Re: 15kva 14.4 kV Transformer.. (fwd)
>> >
>> > Dr,
>> >
>> > That is big news.  When did this occur?
>> >
>> > How about some specs on the coil?
>> >
>> > Schematics of the electronics?  IGBT part numbers?
>> >
>> > Photos?
>> >
>> > Terry Blake
>> > Coiling in Chicago
>> > http://www.tb3.com/tesla/index.html
>> >
>> >
>> >
>> > ----- Original Message -----
>> > From: "Tesla list" <tesla@xxxxxxxxxx>
>> > To: <tesla@xxxxxxxxxx>
>> > Sent: Thursday, December 21, 2006 11:14 AM
>> > Subject: Re: 15kva 14.4 kV Transformer.. (fwd)
>> >
>> >
>> >> Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx>
>> >>
>> >>
>> >>
>> >> ---------- Forwarded message ----------
>> >> Date: Thu, 21 Dec 2006 09:15:47 -0700
>> >> From: resonance <resonance@xxxxxxxxxxxx>
>> >> To: Tesla list <tesla@xxxxxxxxxx>
>> >> Subject: Re: 15kva 14.4 kV Transformer.. (fwd)
>> >>
>> >>
>> >>
>> >> We did 24 hrs on a solid state DRSSTC.  It produced 8 ft sparks and 
>> >> ran
>> > all
>> >> day and all night until 10 AM the next morning.  IGBTs were very cool 
>> >> as
>> >> they were underrated by 100% for their current load and fan cooled. 
>> >> The
>> > sec
>> >> coil held up without any flashovers.
>> >>
>> >> Dr. Resonance
>> >>
>> >>
>> >> >
>> >> > Speaking of this, has anyone here ever done a long run on a TC? I 
>> >> > mean,
>> >> > days! That would be cool to rate all the components, caps etc. and 
>> >> > turn
>> > it
>> >> > on non stop! It would be the best test of a real live practical TC! 
>> >> > Any
>> >> > comments?
>> >>
>> >>
>> >>
>> >>
>> >
>> >
>> >
>> >
>>
>>
>>
>>
>>
>
>
>
>