[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [TCML] IGBT?
I am aware of this.
On 4hv I found a few posts where people have gotten really good deals on these guys, figured it can't hurt to ask. =)
My motivation stems from the fact that if I can tell my buddies that I can get the most expensive part for a reasonable price (everything else seems pretty cheap compared), it will help us in acquiring college funding for the project when they present the project idea.
As well as the fact that I can always run them at a lower current, but the small ones I can't run higher, giving us more screw up room.
Thanks,
John "Jay" Howson IV
----- Original Message -----
From: "Finn Hammer" <f-h@xxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Thursday, September 22, 2011 5:15:46 PM
Subject: Re: [TCML] IGBT?
Hold your horses, Jay.
One single CM600 is good for 5 feet of solid connecting spark, as seen
here:
http://www.youtube.com/watch?v=vK17-CoB7LE [http://www.youtube.com/watch?v=vK17-CoB7LE]
Cheeers, Finn Hammer
----- Original meddelelse -----
> Fra: jhowson4@xxxxxxxxxxx
> Til: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> Dato: Tor, 22. sep 2011 03:36
> Emne: Re: [TCML] IGBT?
>
> Gotchyea, the rise over fall time makes perfect sense now. Thank you
> for the link.
>
> Well I guess I will have to get some IGBTs and test them out, when
> the time comes. =)
> But having bricks would indeed be much nicer, just from looking at
> them I can see that they are rugged.
>
> Does anyone have any of the cm600's or close to that for sale?
>
> Thanks,
> John "Jay" Howson IV
>
> ----- Original Message -----
> From: "Finn Hammer" <f-h@xxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Wednesday, September 21, 2011 2:42:48 AM
> Subject: Re: [TCML] IGBT?
>
> About how much current you can push trough a semiconductor.
>
> Manufacturers test theit devices to a level where they are willing to
> back them up with at least their name and reputation. Not saying thay
> will ever replace them for you.
> In tesla hobby community, it has become current practice to test the
> devices to destruction, or in the case as with real professionals
> like
> Terry Fritz, to just under destruction.
> I recall seing scope shots of the voltage drop across these IGBT´s at
> a
> point where they started to drift into a situation where their
> resistance
> would rise, and heat is generated violently. As far as I understand,
> the
> devices are forced to turn off ever so slightly, because the gate
> voltage
> is lowered due to some paracitic capacitance acting on the rising
> current, and therefore cannot be counteracted upon.
> The device is going out of saturation, I believe is the term applying
> to
> that situation.
> So to the average joe, like myself, it is "suck it and see" and I
> have
> successfully driven CM600´s beyond the 8kA mark without blowing tham
> up.
> But no telling how long they will last.
>
> I do have one coil running now in museum duty on a daily basis for
> the
> 6th year in a row, and if I was more scientifically inclined, I guess
> I
> would calculate the primary current in it, to support my words with
> hard
> data.
>
> So this didn´t help much, but then, with all due respect, you can´t
> expect detailed help before there is a committed design to select
> devices
> against. I would suggest bricks anytime, though, coz thay are
> rugged-fer
> sure.
>
> Now the trisils:
> When you get to a design that is actually going to be built, I will
> find
> a nice little program that Terry wrote back then, it calculates, and
> plots, the current trough trisils and IGBT, depending on the voltage,
> primary inductance and the size of the tank cap.
> The current trough the trisils can only rise to so much due to the LC
> time constant, and the turn on time of the IGBT, so these are the
> parameters you play with.
> The Trisils just short the voltage across the IGBT for long enough to
> turn them on, so that they themselves can short out, and take over.
> As
> soon as the voltage is kept low by the IGBT´s, the trisils will
> recover
> and be armed and ready for the next shot.
> The 10/1000 is a standard lightning related pulse, it should be
> gooogleable.
> Ok, just did:
> It describes a pulse that rises in 10uS and decays in 1000uS. That is
> a
> very wide pulse, and in radio frequency the device will be able to
> tolerate much higher peak curents.
> http://www.semtech.com/images/datasheet/si96-03_ag.pdf
> [http://www.semtech.com/images/datasheet/si96-03_ag.pdf]
>
> Cheers, Finn Hammer
> ----- Original meddelelse -----
>
> > Fra: jhowson4@xxxxxxxxxxx
> > Til: tesla list <tesla@xxxxxxxxxx>
> > Dato: Ons, 21. sep 2011 02:03
> > Emne: [TCML] IGBT?
> >
> > Hello all,
> >
> > I am attempting to figure out how to properly choose an IGBT for a
> > SISG board.
> > Not sure if I will be building one yet, but more of a learning and
> > trying to figure everything out kind of thing. so I have been using
> > my current coil as a base design, just for the purposes of figuring
> > this out on paper.
> >
> > The schematic calls for an IRGPS60B120KDP
> > But the current to pulse frequency characteristics are not listed
> in
> > the datasheet.
> >
> > How does one determine if the IGBT will be acceptable for my
> > particular coil set up?
> > Java TC tells me that my primary current is close to 400 amps peak
> > current (not that the coil that might be built would have that
> > primary current)
> > I read some where (wish I remembered where) that these were fine up
> > to an 800amp primary peak current...is that way off base, and if
> not
> > where did that number come from?
> >
> >
> > I am having a similar issue with the SIDACs which I have been
> > informed the proper replacement is called a TRISIL
> > specifically this one
> >
> http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00001359.pdf
> >
> > Once again I am not sure why. Probably because I don't understand
> the
> > format. Like in the section labeled repetitive peak pulse current
> the
> > value is defined as 10/1000 us being 30A at first i though that it
> > was a simple fraction expressing that it could handle a 30 amp
> pulse
> > every 10ns, but apparently that is not right per a random forum
> post
> > I found... somewhere... So what exactly does 10/1000 mean?
> >
> >
> >
> > Thank you to anyone willing to help me learn,
> > John "Jay" Howson IV
> >
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla