Re: SSgap Diagrams

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Marco Denicolai by way of Terry Fritz <twftesla-at-uswest-dot-net>" <marco.denicolai-at-tellabs-dot-com>

Terry,

I see you plan to use the IRG4PH50UD IGBT. I used the IRG4PH40UD and
before having it working I filled a bean can with burned IGBTs. And
think that my maximum current (besides spikes) was about 30A!
To avoid you filling a trash can (sensibly bigger than a bean can, at
least here in Finland!) with burned IGBTs I strongly recommend you to
read my paper about problems and solutions with the Thor CCPS located at

http://www.saunalahti.fi/dncmrc/papers.html

Second paper from up, chapter "Problems encountered and solutions".
You'll see you have better to use a gate resistor, etc. I suggest also
to read as much as you can about gate drive techniques from available
application notes.

More, I think you would benefit from a simple current limiting system.
What I have been using successfully is just a 2N2222 and a SMD (thick
film, low value) resistor for each IGBT: that allowed me to use just ONE
bean can. See the driver schematics in my paper, which is an UPDATED
version of the schematics available on my web pages.

Regards


Tesla list wrote:
> 
> Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>
> 
> Hi All,
> 
> Since there is a lot of interest in my little solid state gap project, I
> posted a few diagrams and schematics at:
> 
> http://hot-streamer-dot-com/TeslaCoils/MyCoils/SolidStateCoil/SSgap3-29-01/
> 
> I left out some of the plain Jane details of the controller's electronics
> (lots of LMC555 and 74HCT stuff) since it is messy, but this will give you
> the idea as to what it is about...  The real key is the Power_block,
> Sync_sender, and Control_Panel stuff since that shows mostly what it is and
> how it works.  These are still real rough but show the basics (I just
> noticed the optical sender's logic is reversed ;-)).  I expect to be
> putting a lot of time into this next week. ;-)))
> 
> Cheers,
> 
>         Terry

-- 
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 Marco Denicolai           Senior Design Engineer 
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