Yes, I know - the output devices turn off slowly. I'm just sticking to the point I made back in post #8
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Sounds like we're on the same page then . I'm hoping that, with the models from Steve's sim, I can replicate his results. Intusoft has a weird way of modeling power output devices. They are subcircuits with two individual devices, plus a resistor. One of them has an external base spreading resistor, the other not. I'll have to look in their manuals to see why they do that. Maybe they don't support XCJC and this is how they work around that?
.SUBCKT QSC3281 1 2 3
* TERMINALS: C B E
* 200 Volt 15 Amp SiNPN Power Transistor 12-03-1991
Q1 1 2 3 QPWR .67
Q2 1 4 3 QPWR .33
RBS 2 4 9.5
.MODEL QPWR NPN (IS=1.63P NF=1 BF=150 VAF=254 IKF=12 ISE=1.34N NE=2
+ BR=4 NR=1 VAR=20 IKR=16.5 RE=22.1M RB=4 RBM=.4 IRB=5.556U RC=4.84M
+ CJE=481P VJE=.6 MJE=.3 CJC=312P VJC=.22 MJC=.2 TF=5.33N TR=204N)
+ XTB=1.5 PTF=120 XTF=1 ITF=9.6)
.ENDS
. I'm hoping that, with the models from Steve's sim, I can replicate his results. Intusoft has a weird way of modeling power output devices. They are subcircuits with two individual devices, plus a resistor. One of them has an external base spreading resistor, the other not. I'll have to look in their manuals to see why they do that. Maybe they don't support XCJC and this is how they work around that?.SUBCKT QSC3281 1 2 3
* TERMINALS: C B E
* 200 Volt 15 Amp SiNPN Power Transistor 12-03-1991
Q1 1 2 3 QPWR .67
Q2 1 4 3 QPWR .33
RBS 2 4 9.5
.MODEL QPWR NPN (IS=1.63P NF=1 BF=150 VAF=254 IKF=12 ISE=1.34N NE=2
+ BR=4 NR=1 VAR=20 IKR=16.5 RE=22.1M RB=4 RBM=.4 IRB=5.556U RC=4.84M
+ CJE=481P VJE=.6 MJE=.3 CJC=312P VJC=.22 MJC=.2 TF=5.33N TR=204N)
+ XTB=1.5 PTF=120 XTF=1 ITF=9.6)
.ENDS
Not directly. That's a really good thing to look at in the models though. It could explain the differences we're seeing.
Edit: The more I think about this, the more I think that could be the explanation. There's some reverse parameters, that can't be obtained from the data sheets, that may hold the key.
Edit: The more I think about this, the more I think that could be the explanation. There's some reverse parameters, that can't be obtained from the data sheets, that may hold the key.
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When I was a kid I thought that Meadowlark Lemon and the Harlem Globe Trotters could beat any NBA team hands down. We all have our own view on reality.
Nicola Tesla WAS eccentric and on some fronts totally wacked.
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It might be true (depending on state of development of local cultural standards), but it's for sure completely irrelevant in full awareness of his incomparable contribution to well-being of the mankind. AC (not to mention his other achievements) is still fundamental to modern civilization.
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Would this indicate that someone characterized these devices on their own? This is serious work in terms of the equipment and experts to drive it. I would not be easily convinced that the model libraries provided by most commercial SPICE packages are not just compendiums of the same ones you can download for free (usually) from the device manufacturers.
Good to see you back on the case.
NOTE: I recognize Tesla's contributions. I just don't think the extremes of Galileo and Tesla are comparable to the various ways you can connect 8 transistors.
Except if someone finds a way to connect them as a tachyon generator or a fusion reaction stabilizer
Intusoft has a tool called SpiceMod that allows the user to enter some device datasheet parameters, from which it computes the SPICE model. PSPICE has a similar tool. I have an old DOS evaluation version of SpiceMod they used to offer for free, which I use to guess some of the parameters that can't be obtained from the datasheet, such as reverse Early Voltage. I don't know what formulas it's using for this or where they got them. It's unlikely they're using an Agilent semiconductor parameter analyzer and IC-CAP software. That's big bucks and a huge time investment. The Wikipedia entry for Intusoft says they have 12 employees, so they're a really small outfit. I suspect they're just using SpiceMod to generate the models.
At this point my goal is only to duplicate Steve's simulation results. I'll need to use LTspice for this, since the ICAP demo device count limit is exceeded by this circuit. If that's successful, I'll post that simulation so anybody with LTspice can look at it and see the same thing Steve is seeing.
I think it would be very nice if Steve could post the various models he is using.
I’m sure he can export them as text files.
As far as I know Infusoft is using regular spice models, not MEXTRAM models.
Home of Mextram
Cheers
I’m sure he can export them as text files.
As far as I know Infusoft is using regular spice models, not MEXTRAM models.
Home of Mextram
Cheers
>It's unlikely they're using an Agilent semiconductor parameter analyzer and IC-CAP software.
I just attended an afternoon meeting to strategize on extending our models to 50GHz. The guys that do this stuff are amazing (skin effect on 100u long metal runs). The S parameter data lined up within a dB or so from .1 to 50G.
I just attended an afternoon meeting to strategize on extending our models to 50GHz. The guys that do this stuff are amazing (skin effect on 100u long metal runs). The S parameter data lined up within a dB or so from .1 to 50G.
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We've been here before, unproductively. I tried to step back and look at the kind of things you could even do with pencil and paper. After all even if some poorly modeled charge storage effect was at work, it would stop working at some low (quasi) DC frequency.
Guys, Steve has provided all the models, so that's a non-issue. They are in the netlist file attached to this post. Just have a look with a text editor. That's why I'm very optimistic about being able to duplicate his results.
I can reverse engineer the schematic from the netlist if need be.
I started reading from where I left off yesterday. Can someone tell me where some of my posts went? And why? I had quoted GK in a post that is now gone. I also see that his post was changed after I quoted from it. Are there new rules I should know about? I certainly didn't say anything that should have been objectionable.
Holy shiet
- how are your Magnepan's and amp etc.??? I see that you are on the computer which is good because I know that it is located in the basement - but I'm wondering if you are sitting in your chair or floating around in some type of small boat or wearing fishing waders? 
How is the workshop (and your stash of parts)?
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