Slinky Question

[DarkMatter]

On Sat, 13 Mar 2004 08:19:07 -0700, Jim Thompson
<thegreatone@example.com> Gave us:

On Sat, 13 Mar 2004 07:18:31 -0800, John Larkin
jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote:

On Sat, 13 Mar 2004 13:57:28 GMT, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Sat, 13 Mar 2004 07:20:11 +0000, the renowned John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Jim Thompson
thegreatone@example.com> wrote (in <fsp450lbhkksqv6p7oda87us8cc9o884nn@
4ax.com&gt about 'Slinky Question', on Fri, 12 Mar 2004:
Wanna borrow my
Glock ?

You want to threaten them with a glockenspiel? That's cruel and unusual
punishment indeed!!

Time for them to face the music.

That would even up the score for sure.

John


Now *that* was punny ;-)

Watch what you say around here. You could get yourself into Treble.

 

[DarkMatter]

On Sat, 13 Mar 2004 15:42:32 -0000, "Mjolinor" <mjolinor@hotmail.com>
Gave us:

"John Larkin" <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote in
message news:3h9650plppgbd9g6eqk3liqjvqdope5qmm@4ax.com...
On Sat, 13 Mar 2004 13:57:28 GMT, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Sat, 13 Mar 2004 07:20:11 +0000, the renowned John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Jim Thompson
thegreatone@example.com> wrote (in <fsp450lbhkksqv6p7oda87us8cc9o884nn@
4ax.com&gt about 'Slinky Question', on Fri, 12 Mar 2004:
Wanna borrow my
Glock ?

You want to threaten them with a glockenspiel? That's cruel and unusual
punishment indeed!!

Time for them to face the music.

That would even up the score for sure.

John



Perhaps we should all help orchestrate it?

I thought this group was about conductors....

 

[John Larkin]

On Sat, 13 Mar 2004 08:03:53 -0800, DarkMatter
<DarkMatter@thebarattheendoftheuniverse.org> wrote:

On Sat, 13 Mar 2004 15:42:32 -0000, "Mjolinor" <mjolinor@hotmail.com
Gave us:


"John Larkin" <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote in
message news:3h9650plppgbd9g6eqk3liqjvqdope5qmm@4ax.com...
On Sat, 13 Mar 2004 13:57:28 GMT, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Sat, 13 Mar 2004 07:20:11 +0000, the renowned John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Jim Thompson
thegreatone@example.com> wrote (in <fsp450lbhkksqv6p7oda87us8cc9o884nn@
4ax.com&gt about 'Slinky Question', on Fri, 12 Mar 2004:
Wanna borrow my
Glock ?

You want to threaten them with a glockenspiel? That's cruel and unusual
punishment indeed!!

Time for them to face the music.

That would even up the score for sure.

John



Perhaps we should all help orchestrate it?

I thought this group was about conductors....

Ooh, you're sharp today.

John

 

[John Fields]

On Sat, 13 Mar 2004 07:59:03 -0800, John Larkin
<jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote:

On Sat, 13 Mar 2004 15:42:32 -0000, "Mjolinor" <mjolinor@hotmail.com
wrote:


"John Larkin" <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote in
message news:3h9650plppgbd9g6eqk3liqjvqdope5qmm@4ax.com...
On Sat, 13 Mar 2004 13:57:28 GMT, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Sat, 13 Mar 2004 07:20:11 +0000, the renowned John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Jim Thompson
thegreatone@example.com> wrote (in <fsp450lbhkksqv6p7oda87us8cc9o884nn@
4ax.com&gt about 'Slinky Question', on Fri, 12 Mar 2004:
Wanna borrow my
Glock ?

You want to threaten them with a glockenspiel? That's cruel and unusual
punishment indeed!!

Time for them to face the music.

That would even up the score for sure.

John



Perhaps we should all help orchestrate it?


We could band together and arrange that.

---
That would be sharp; see?

--
John Fields

 

[Bill Garber]

"John Larkin" <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com>
wrote in message
news:qnc650p5l1mv9m4cqqr29je50uqm9i1frb@4ax.com...
: On Sat, 13 Mar 2004 08:03:53 -0800, DarkMatter
: <DarkMatter@thebarattheendoftheuniverse.org> wrote:
:
: >On Sat, 13 Mar 2004 15:42:32 -0000, "Mjolinor"
<mjolinor@hotmail.com>
: >Gave us:
: >
: >>
: >>"John Larkin" <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com>
wrote in
: >>message news:3h9650plppgbd9g6eqk3liqjvqdope5qmm@4ax.com...
: >>> On Sat, 13 Mar 2004 13:57:28 GMT, Spehro Pefhany
: >>> <speffSNIP@interlogDOTyou.knowwhat> wrote:
: >>>
: >>> >On Sat, 13 Mar 2004 07:20:11 +0000, the renowned John
Woodgate
: >>> ><jmw@jmwa.demon.contraspam.yuk> wrote:
: >>> >
: >>> >>I read in sci.electronics.design that Jim Thompson
: >>> >><thegreatone@example.com> wrote (in
<fsp450lbhkksqv6p7oda87us8cc9o884nn@
: >>> >>4ax.com&gt about 'Slinky Question', on Fri, 12 Mar 2004:
: >>> >>>Wanna borrow my
: >>> >>>Glock ?
: >>> >>
: >>> >>You want to threaten them with a glockenspiel? That's
cruel and unusual
: >>> >>punishment indeed!!
: >>> >
: >>> >Time for them to face the music.
: >>>
: >>> That would even up the score for sure.
: >>>
: >>> John
: >>
: >>Perhaps we should all help orchestrate it?
: >
: > I thought this group was about conductors....
:
: Ooh, you're sharp today.
:
: John

I'm a little "flat" today, what was the "bass"
topic of this thread? 8o)

Bill @ GarberStreet Enterprizez };-)
Web Site - http://garberstreet.netfirms.com
Email - willy4SPAM6pa@comXcast.net
Remove - SPAM and X to contact me



---
This email ain't infected, dude!

Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.593 / Virus Database: 376 - Release Date: 2/27/04

 

[Bill Sloman]

John Fields <jfields@austininstruments.com> wrote in message news:<usk45095c8rel0r3mqqvaro1nnjkaqvrdk@4ax.com>...

On 12 Mar 2004 15:56:49 -0800, bill.sloman@ieee.org (Bill Sloman) wrote:

John Fields <jfields@austininstruments.com> wrote in message news:<bfi350tjsc1fj9s9ajuc9qf702l40i7o79@4ax.com>...
On 12 Mar 2004 02:42:29 -0800, bill.sloman@ieee.org (Bill Sloman) wrote:

John Fields <jfields@austininstruments.com> wrote in message news:<6p3250pf42hlj67ebf4265v1vggg05nh5b@4ax.com>...
On 11 Mar 2004 15:26:08 -0800, bill.sloman@ieee.org (Bill Sloman) wrote:


Discourse? A long word to apply to kindergarten-level content. Been
reading "how to improve your word power" have you?

---
Yes, constantly, but no matter what I do I seem unable to please the
dregs of society. Particularly the likes of you, who is only interested
in being combative and never has anything good to say about anything.

Except possibly about gun control? Though the absence of gun control
in Texas may edit your contributions somewhat earlier than might
otherwise happen.

---
No, idiot, there's nothing good about gun control, because it dumbs
everyone down to the least common denominator.

You are the idiot. My approval of gun control falsifies your foolish
claim that I never have anything good to say about anything.

---
Just because it sounds, to you, like you're saying a good thing doesn't
mean that it _is_ a good thing.

Very possibly, but I've still falsified your foolish claim, and you
are too dim to realise it and shut up.

<snipped the rest of your equally ill-founded response>

-------
Bill Sloman, Nijmegen

 

[Bill Sloman]

John Woodgate <jmw@jmwa.demon.contraspam.yuk> wrote in message news:<bJLDEVArYrUAFwpL@jmwa.demon.co.uk>...

I read in sci.electronics.design that Jim Thompson
thegreatone@example.com> wrote (in <fsp450lbhkksqv6p7oda87us8cc9o884nn@
4ax.com&gt about 'Slinky Question', on Fri, 12 Mar 2004:
Wanna borrow my
Glock ?

You want to threaten them with a glockenspiel? That's cruel and unusual
punishment indeed!!

And quite unnecessary - at least as far as I am concerned. The
Netherlands isn't short of music. The local chamber-music society
imported the Skampa Quartet last Tuesday, and the played (amongst
other things) Dovorak's five bagatelles for two violins, a chello and
a harmonium.

At a much lower level, I can't got to the supermarket without having
to listen to a harmonica (reasonably expertly played, but still a
harmonica) and this morning's shopping took me past the regular
hand-cranked barrel-organ (and the guy was cranking it too fast, as
always).

Even my (field)hockey club has been known to manifest a brass band
(known as the Almost Good Band) though I wouldn't have invited my
piano teacher to listen to them.

-------
Bill Sloman, Nijmegen

 

[Charles Edmondson]

John Woodgate wrote:

I read in sci.electronics.design that Jim Thompson
thegreatone@example.com> wrote (in <fsp450lbhkksqv6p7oda87us8cc9o884nn@
4ax.com&gt about 'Slinky Question', on Fri, 12 Mar 2004:

Wanna borrow my
Glock ?


You want to threaten them with a glockenspiel? That's cruel and unusual
punishment indeed!!

Oh My! Torture by improperly played percusion instrument! Truly cruel
and unusual punishment!

Jim, that is LOW, oh so LOW! I love it!

--
Charlie
--
Edmondson Engineering
Unique Solutions to Unusual Problems

 

....and you decided to post this to alt.binaries.schematics.electronic,
sci.electronics.cad, sci.electronics.design, and sci.electronics.misc - why?

Charles Edmondson <edmondson@ieee.org> says...

John Woodgate wrote:
I read in sci.electronics.design that Jim Thompson
thegreatone@example.com> wrote (in <fsp450lbhkksqv6p7oda87us8cc9o884nn@
4ax.com&gt about 'Slinky Question', on Fri, 12 Mar 2004:

Wanna borrow my
Glock ?


You want to threaten them with a glockenspiel? That's cruel and unusual
punishment indeed!!

Oh My! Torture by improperly played percusion instrument! Truly cruel
and unusual punishment!

Jim, that is LOW, oh so LOW! I love it!

--
Charlie
--
Edmondson Engineering
Unique Solutions to Unusual Problems

 

[Robert L Rauck]

Manfred Kellermann wrote:

Hey all,

i have to perform a windows port of spice3-engine for educational purposes.
I searched for the files Spice3f5EngineSource.zip and SpiceEngineVC.zip
(provided by Kevin Aylward from anasoft some years ago) but i had no luck.
Is anybody out there, who can make them available to me?

Manfred


Had you considered one of the commercially available Spice 3 Windows

simulators?

http://www.intusoft.com/products/icap4stu.htm

Robert L Rauck

 

[Kevin Aylward]

Robert L Rauck wrote:

Manfred Kellermann wrote:

Hey all,

i have to perform a windows port of spice3-engine for educational
purposes. I searched for the files Spice3f5EngineSource.zip and
SpiceEngineVC.zip (provided by Kevin Aylward from anasoft some years
ago) but i had no luck. Is anybody out there, who can make them
available to me?

Manfred


Had you considered one of the commercially available Spice 3 Windows
simulators?

http://www.intusoft.com/products/icap4stu.htm

But thats crap

Anyway, the superspice spice engine is standalone. It can be ran from
the command line, and has no restrictions.

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

"quotes with no meaning, are meaningless" - Kevin Aylward.

 

[Dale Chisholm]

I'll second the vote for Kielkowski's books! He seems to write for us
"mere mortals" who have access to general-purpose test gear, rather
than device manufacturers who can actually measure the dozens of
esoteric parameters that are available in many spice models. So if
you can get a decent model from a manufacturer, use it - hopefully,
the mfgr has measured and characterized parameters that you have no
practical way to access.

(Having said that - I've come across some pretty shoddy models
published by manufacturers. Very few even try to tell you what
characteristics are modeled well, poorly, or not at all. E.g., the
original Boyle opamp models, which do a very poor job of modeling the
interactions between opamp and power supply, are still being published
some 20 years after MUCH better models were available.)

Your diode is a case in point: with a dozen measurements, or even
points picked off a typical conduction curve, accurately determining
Is, N, and Rs is an interesting exercise in curve-fitting with MATLAB,
Excel, etc. Modeling the DC forward conduction can then be done quite
accurately, and for a lot of simulations that's all you need - the
other parameters can be left to any convenient default value. But if
(for instance) junction capacitance at particular (forward or reverse)
bias points, or accurate reverse breakdown behavior, or transit times,
matter in your application then you'll have to resort to more
elaborate models, and will need to make more exotic measurements.

"Tim Stinchcombe" <timng1@tstinchcombe.freeserve.co.uk> wrote in message news:<c22m5n$vqp$1@newsg4.svr.pol.co.uk>...

I'd suggest trying to get hold of a copy of Ron Kielkowski's 'SPICE
Practical Device Modeling' (McGraw-Hill, 1995) through your library. In it
he describes how to do just what you are trying to do. For example, for a
diode, a plot of log(I) vs V will give you IS, N and RS. It is easy to
manipulate I=Is*exp(qV/NkT) to get log(I)=qV/NkT+log(Is): so the gradient is
q/NkT, which'll give you N; the y-axis intercept is log(Is), hence Is; RS is
a little harder to describe - find that V where the straight-line portion of
the line intercepts the Imax level, i.e. the level for the biggest value of
measured I, then RS=(Vmax-this)/Imax. You'll then have a model which, for DC
analyses at least, will match your data. Other parameters for AC analyses
and things needing capacitances etc. can be extracted similarly if you have
the appropriate data/measurements. I find both Kielkowski's books to be very
good (but pricey...)

Tim

--
__________________________________________________________
Tim Stinchcombe

Cheltenham, Glos, UK

"AJ" <aj.usenetspam@serato.com> wrote in message
news:387bcaab.0402210155.ce1191b@posting.google.com...
I am trying to create a device model for a small signal diode. The
problem is, I don't know how to translate real world specs into the
numbers that SPICE wants. The most useful piece of information to me
right now, is what Area Factor means, but I can't seem to get a
straight answer out of the internet on that one. Sure, a lot of sites
talk about it, but they don't say what it *is* or how to calculate it.

I know this is a pretty basic thing, but I am totally new to circuit
simulation. I figure that the combination of Area Factor, and one of
the other numbers inside the model determine the basic characteristics
of the diode, but I don't know how.

Any starting hints?

 

[Svennis]

Hi Blake!

If you can't copy them from that old installation try look at Borland
company borland.com

VCL50.BPL stands for Visual Component Library 5.0 Borland Procedure Library
or something. It shipps with a programming development product called Delphi
(CBuilder). Maybe their free trial software includes one copy of the files.
Have a look.

http://www.borland.com/products/downloads/download_delphi.html

or search the net, there are out there for sure :-{

Ride on
Svennis


"Blake" <KiwiXPlant@NoSpam.adelphia.net> wrote in message
news:Yu-dnXz-U7Fj5MfdRVn-jg@adelphia.com...

My employer has a policy; Every pc has to be updated after three years.
Well, I was just upgraded to a new machine with XP Pro today, and now my
copy of Protel99SE won't run. Error messages about "unable to find
VCL50.BPL" and "unable to find CRSTL50.BPL". Protel (now Altium) no longer
"supports" 99SE, so I'm left to look for support from my fellow users.

Does anyone have experience with this combination of software and
operating
system? Will it be a simple matter of inserting a few run time libraries
into my system directory, or is it a hopeless cause? I'm only an
occasional
user, so I don't want to invest the $3500 in a software upgrade.

Your suggestions are welcome. Thanks.

 

[stefan morley]

Hi Blake.

I was running DXP at work (on XP pro) and didn't like it. So I downgraded
to 99SE. I had no problems. The SE I installed is SP6. Don't know if
this makes a difference.

Stefan

years.

Well, I was just upgraded to a new machine with XP Pro today, and now my
copy of Protel99SE won't run. Error messages about "unable to find
VCL50.BPL" and "unable to find CRSTL50.BPL". Protel (now Altium) no
longer
"supports" 99SE, so I'm left to look for support from my fellow users.

Does anyone have experience with this combination of software and
operating
system? Will it be a simple matter of inserting a few run time libraries
into my system directory, or is it a hopeless cause? I'm only an
occasional
user, so I don't want to invest the $3500 in a software upgrade.

Your suggestions are welcome. Thanks.

 

[Brad Velander]

Blake,
If your problem is as simple as Svennis suggests then you should
just be able to do a re-install from the original disks. To the best of my
recollection Protel installs the correct versions of these files during
install. I would have to believe that your upgrade wrote newer versions over
the old files.

For ongoing support I would suggest that you join the Protel listserver that
can be found at:

http://www.techservinc.com/protelusers/index.html

The members are worldwide and they include some of the most knowledgeable
Protel users around.

--
Sincerely,
Brad Velander

"Svennis" <someone@nnoossppaamm.com> wrote in message
news:bFw6c.52750$mU6.219935@newsb.telia.net...

Hi Blake!

If you can't copy them from that old installation try look at Borland
company borland.com

VCL50.BPL stands for Visual Component Library 5.0 Borland Procedure
Library
or something. It shipps with a programming development product called
Delphi
(CBuilder). Maybe their free trial software includes one copy of the
files.
Have a look.

http://www.borland.com/products/downloads/download_delphi.html

or search the net, there are out there for sure :-{

Ride on
Svennis

 

[te]

PCB Altium (Protel) 2004 -

P-CAD V2002 (c) Altium CD NR 11 286

PROTEL ALTIUM DESIGN EXPLORER V 7.0.737 WinNT2000XP 9718

week 36/2002

Protel.Altium.DXP.Suite.v7.0.749.Keygen.and.Patch.

week 35/2002

Protel.Altium.DXP.V.7.0.WinNT2000XP

19.02.00 Protel 99 SE Service Pack 4

18.12.99 Protel 99 SE 6.05 Incl SP3

10-24-0| CircuitMaker 2000 (incl SP1) Cracked (c) Protel

If you have Googled your butt off, and haven't come up with anything ..., and
for 14,500 more reasons, please send e-mail,

astra35@freemail.gr, astra35@pathfinder.gr, astra35@mail.gr, astra35@mailbox.gr

 

[Chaos Master]

Dale Chisholm screams:

I'll second the vote for Kielkowski's books! He seems to write for us
"mere mortals" who have access to general-purpose test gear, rather
than device manufacturers who can actually measure the dozens of
esoteric parameters that are available in many spice models. So if
you can get a decent model from a manufacturer, use it - hopefully,
the mfgr has measured and characterized parameters that you have no
practical way to access.

(Having said that - I've come across some pretty shoddy models
published by manufacturers. Very few even try to tell you what
characteristics are modeled well, poorly, or not at all. E.g., the
original Boyle opamp models, which do a very poor job of modeling the
interactions between opamp and power supply, are still being published
some 20 years after MUCH better models were available.)

I think most manufacturers do not make good SPICE models to avoid the chance of
someone "reverse-engineering" their component data.

[]s
--
Chaos MasterŽ - Porto Alegre, RS, Brazil
irc.brasnet.org - #xlinuxnews and #poa
marreka.no-ip.com (ainda năo pronto)
LRU #327480

 

[Kevin Aylward]

Chaos Master wrote:

Dale Chisholm screams:
I'll second the vote for Kielkowski's books! He seems to write for
us "mere mortals" who have access to general-purpose test gear,
rather than device manufacturers who can actually measure the dozens
of esoteric parameters that are available in many spice models. So
if you can get a decent model from a manufacturer, use it -
hopefully, the mfgr has measured and characterized parameters that
you have no practical way to access.

(Having said that - I've come across some pretty shoddy models
published by manufacturers. Very few even try to tell you what
characteristics are modeled well, poorly, or not at all. E.g., the
original Boyle opamp models, which do a very poor job of modeling the
interactions between opamp and power supply, are still being
published some 20 years after MUCH better models were available.)

I think most manufacturers do not make good SPICE models to avoid the
chance of someone "reverse-engineering" their component data.

Not really likely. In most cases its simply the effort involved.


Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

"quotes with no meaning, are meaningless" - Kevin Aylward.

 

[Dale Chisholm]

"Kevin Aylward" <kevindotaylwardEXTRACT@anasoft.co.uk> wrote in message news:<dZS6c.25$Kt4.6@newsfep3-gui.server.ntli.net>...

Chaos Master wrote:
Dale Chisholm screams:

.. . .

(Having said that - I've come across some pretty shoddy models
published by manufacturers. Very few even try to tell you what
characteristics are modeled well, poorly, or not at all. E.g., the
original Boyle opamp models, which do a very poor job of modeling the
interactions between opamp and power supply, are still being
published some 20 years after MUCH better models were available.)

I think most manufacturers do not make good SPICE models to avoid the
chance of someone "reverse-engineering" their component data.

Not really likely. In most cases its simply the effort involved.

Kevin Aylward

Since I've never been very close to device manufacturing, I don't
really know - but I suspect Kevin's right.

It doesn't take much effort to slap together the sort of model that
mimics the calculations one might do on a paper napkin while waiting
for your lunch order. And it's not useful for much more than finding
arithmetic errors in that napkin calculation, but it lets the
marketing guys loudly proclaim, "We support your design efforts by
giving you Spice models of our products!".

Speaking as a board-level designer, who must use components that are
readily available (and, of course, cheap!), simulation is almost
worthless if it only verifies my calculations. Simulation starts to
have real value when it shows things that are either too complex or
too tedious for me to uncover with calculator and spreadsheet. One of
Kielkowski's themes is that it doesn't take Herculean efforts to
quantify first-order imperfections in common components and include
their effects in modeling efforts. I find THAT extremely useful! Not
that the more detailed models have ever totally upset my initial
calculations, though they often show where minor adjustments can make
observable improvements. Rather, they often show the real limits of
product performance. They also give me assurance that my simplifying
assumptions were valid and I really do have a good comprehension of
how this thing I've created will actually work.

So if a manufacturer has put forth the effort to craft more than a
simplistic model, I'm inclined to use his work rather than try to
improve it. Especially if he'll come out and tell you what
characteristics are being modeled, and under what conditions. Calling
on my dusty memories, I recall that Analog Devices and Burr-Brown have
been fairly good in this regard; TI a little less so. On the other
hand, a model whose parameters are sparse or include a lot of the
Spice default values will send me looking for a different model, or
over to the bench for some measurements. It also makes me wonder how
many of their performance claims are more "show" than "substance".

 

[Kevin Aylward]

Dale Chisholm wrote:

"Kevin Aylward" <kevindotaylwardEXTRACT@anasoft.co.uk> wrote in
message news:<dZS6c.25$Kt4.6@newsfep3-gui.server.ntli.net>...
Chaos Master wrote:
Dale Chisholm screams:

. . .

(Having said that - I've come across some pretty shoddy models
published by manufacturers. Very few even try to tell you what
characteristics are modeled well, poorly, or not at all. E.g., the
original Boyle opamp models, which do a very poor job of modeling
the interactions between opamp and power supply, are still being
published some 20 years after MUCH better models were available.)

I think most manufacturers do not make good SPICE models to avoid
the chance of someone "reverse-engineering" their component data.

Not really likely. In most cases its simply the effort involved.

Kevin Aylward

Since I've never been very close to device manufacturing, I don't
really know - but I suspect Kevin's right.

It doesn't take much effort to slap together the sort of model that
mimics the calculations one might do on a paper napkin while waiting
for your lunch order. And it's not useful for much more than finding
arithmetic errors in that napkin calculation, but it lets the
marketing guys loudly proclaim, "We support your design efforts by
giving you Spice models of our products!".

Speaking as a board-level designer, who must use components that are
readily available (and, of course, cheap!), simulation is almost
worthless if it only verifies my calculations.

Well, not really in my book. If the simulation doesn't agree with the
simplified hand hand calculation, one must find out why. However, in
practise, its impossible analytically to solve even a 2 by 2 non-linear
differential equation, let alone a 100 by 100.

Simulation starts to
have real value when it shows things that are either too complex or
too tedious for me to uncover with calculator and spreadsheet.

Actually, anything more than about two transistors, is way too
complicated to understand in, essentially, complete detail.

One of

Kielkowski's themes is that it doesn't take Herculean efforts to
quantify first-order imperfections in common components and include
their effects in modeling efforts.

This is essentially, true. However, understanding the effect of these
first order effects in an actual 100 transistor circuit can be quite
subtle and difficult to predict.

We all like to thing that we are clever enough to go pen an paper route,
but in practise, pretty much only trivial circuits can work first time
without simulation.

I find THAT extremely useful! Not
that the more detailed models have ever totally upset my initial
calculations, though they often show where minor adjustments can make
observable improvements.

Ahmmmm...

Rather, they often show the real limits of
product performance. They also give me assurance that my simplifying
assumptions were valid and I really do have a good comprehension of
how this thing I've created will actually work.

Models often don't have to be that accurate to enable a pretty good
worst case estimate to be made. For example, in SS, if WC models are not
specified, guestimated defaults are made for the main parameters that
effect say, 99% of the response. e.g. capacitances +/- 30%.

If the final design looks then a bit suspect, one can then try and get a
better model or, preferable, try a different design.



Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

"quotes with no meaning, are meaningless" - Kevin Aylward.