Saturation on overload of Andy_C's models
I simulated Toni's excellent amp from #274 of 2stageef-high-performance-class-ab-power-amp-200w8r-400w4r.
The sim has carefully crafted 2sa1837/c4793_a models from Andy_C. andyc.diy-audio-engineering.org/spice_modelsHowever, in this case, the models result in the sim showing 20kHz overload much worse that Toni reports in 'real life'. see post #342.
The models obviously have far too much charge storage on saturation.
Replacing Andy_C's 2sa1837/c4793_a models with Harry Dymond's 2sa1930/c5171_d models shows no blocking at all. We are waiting for Toni to report some overload tests on this earlier model.
I don't believe this sim either as I expect a 'bit' of blocking on recovery from +ve overload with this configuration. Harry has some caveats on his model.
Would any of yus SPICE gurus modify Andy_C's 2sa1837/c4793_a models to show something closer to 'real life' overload in this simple circuit?
I simulated Toni's excellent amp from #274 of 2stageef-high-performance-class-ab-power-amp-200w8r-400w4r.
The sim has carefully crafted 2sa1837/c4793_a models from Andy_C. andyc.diy-audio-engineering.org/spice_modelsHowever, in this case, the models result in the sim showing 20kHz overload much worse that Toni reports in 'real life'. see post #342.
The models obviously have far too much charge storage on saturation.
Replacing Andy_C's 2sa1837/c4793_a models with Harry Dymond's 2sa1930/c5171_d models shows no blocking at all. We are waiting for Toni to report some overload tests on this earlier model.
I don't believe this sim either as I expect a 'bit' of blocking on recovery from +ve overload with this configuration. Harry has some caveats on his model.
Would any of yus SPICE gurus modify Andy_C's 2sa1837/c4793_a models to show something closer to 'real life' overload in this simple circuit?
I imagine you are seeing this with my models as they don't model quasi-saturation. Andy_C really knows his stuff so I wouldn't necessarily hold out much hope of improvement. Having said that, I guess it's possible that the behaviour you're seeing is very sensitive to one or more spice parameters and just a minor tweak will bring the behaviour closer to real life.
We really need Andy_C back on this forum; his input was invaluable.
Moderators, please take note.
I don't think the quasi-sat that keantoken investigates is responsible. Poorer hoe helps reduce the effects of saturation not hinder it.
Looking at AndyC's http://andyc.diy-audio-engineering.org/spice_models_2.html shows Cob & Cib is practically unchanged through Vce=0.
My guess is the huge fall in ft with current. Gummel-Poon and the other exotic models are simple refinements of Ebers-Moll which sims ft with large Cbe.
But a clamping diode from VAS output to input cures the big blocking so it's got to be something that happens when Vce becomes small.
Anyone got any ideas? I just want to tweak AndyC's a1837/c4793_a models so it ju..usts reflects the 20kHz overload recovery that Toni reports.
Harry, any idea how to tweak your a1930/c5171_d models to show 'some' blocking? That's if Toni reports blocking with 1930/5171
I'm just a SPICE newby
where to find npn/pnp darlington symbol for LTspiceIV/lib/sym ?
i have a few darlington models in library (BD679a from ON site) but if i understood right they are not asociated with any symbol,and therefore it doesn´t work properly.
i would apreacheate any help,since i just today instaled this program.
i have a few darlington models in library (BD679a from ON site) but if i understood right they are not asociated with any symbol,and therefore it doesn´t work properly.
i would apreacheate any help,since i just today instaled this program.
You should check the LTSpice Yahoo group, they have everything, although you will need to thumb through the files.
You don't necessarily need a Darlington symbol. You can CTL-Rclick on the transistor symbol, change prefix to X. Then paste your model onto the schematic, and name the transistor the same as the model. If the pin order for both match, you'll have a transistor symbol that uses the Darlington model.
I would do this first in order to verify the Darlington model is even worth using, and if it bothered me I would create my own darlington symbols or download one from the Yahoo group.
You don't necessarily need a Darlington symbol. You can CTL-Rclick on the transistor symbol, change prefix to X. Then paste your model onto the schematic, and name the transistor the same as the model. If the pin order for both match, you'll have a transistor symbol that uses the Darlington model.
I would do this first in order to verify the Darlington model is even worth using, and if it bothered me I would create my own darlington symbols or download one from the Yahoo group.
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We really need Andy_C back on this forum; his input was invaluable.
Moderators, please take note.
I second that motion!
We need Andy_C back!
Hi, thanks for your interest in my work. Unfortunately, I have not had time to do any further work on Spice models - sorry.
Out of interest, what are your plans for the 2SA2040?
Files spice
600/5000
Hello community,
I hope you are doing well in these difficult times.
I need your help. I use Eagle + Fusion360 for the realization of my amp. I'm looking for a spice model. It's all new to me. I simulated with NI Multisim. But I want to try with EAGLE which is my official license. The spice models that I miss are:
BZX79-C2V7
BZV60-15
BC327
BC337
BD1396-STU
BF420
BF421
1N5408G
1N4742A
1N4004
TL071
I keep looking on my side. Is there a site with many spice files?
Thank you in advance for your help.
Take care of yourself
Lecalou60
600/5000
Hello community,
I hope you are doing well in these difficult times.
I need your help. I use Eagle + Fusion360 for the realization of my amp. I'm looking for a spice model. It's all new to me. I simulated with NI Multisim. But I want to try with EAGLE which is my official license. The spice models that I miss are:
BZX79-C2V7
BZV60-15
BC327
BC337
BD1396-STU
BF420
BF421
1N5408G
1N4742A
1N4004
TL071
I keep looking on my side. Is there a site with many spice files?
Thank you in advance for your help.
Take care of yourself
Lecalou60