|
Been looking for some components here, there and everywhere, and I am having a hard time finding them. I'm looking for 3 zeners and a power transistor.
?
Zeners:
1N4572A 6.4V Zener
1N5226B 3.3V Zener
1N5241 11V Zener
?
Transistor:
2N3791
?
Any help would be appreciated. I am totally down with trying to model it myself via their datasheets, and have some idea of how to do that but, I've never attempted that before so, any push in that direction would help too. It might help if I could find equivalents that may be in the LTSpice library that I could use or, equivalent enough that I can change some of the it's values in order to create what I need. Of course, I'm checking YT for help in these department but, if there's a model out there, it would be a lot easier. I did find one text doc that is supposed to be a library of models that includes the 1N5226B but, it's very difficult to see what is what in that file. I started re-writing / re-organizing it into something that looks like a library of models but, don't know if it'll amount to anything. I was planning on uploading it here and see what you guys make of it. Let me know.
|
Ivan,
?
When looking for models, consider these:
- Search the Internet (part vendor sites) for "equivalent" parts.
- Go to the group's Files section, and type in the model number in the Search box in the upper right corner.
- Consider omitting the suffix (A or B) if you understand what it does.? Often it does not matter.
- Find a similar zener from among LTspice's built-in diodes.? I recommend this way:
- Start with a Zener symbol, right-click on the symbol, then click "Pick New Diode".
- Now click "Vbrkdn[V]" at the top, THEN click "Type" at the top.? Now they will be sorted into diode types, followed by breakdown voltage.
- Scroll down until you find the Zeners.? Then look for the same or a similar voltage.
- Try to find a diode with similar power ratings.
- Find a similar zener by checking manufacturer's part selector guides; they often list "equivalent" or "replacement" parts.
- For a zener, if you plan to use it only in breakdown, many of the SPICE characteristics won't matter, and you can probably get away with a very crude or approximate model.
?
I found a 1N5226 (no B) model in our Files.? It says its source was Motorola:
* 1N5226 ? ?3.3 Volt ?5% ?W zener diode
.model D1N5226 ?D(Is=31.47f Rs=9.494 Ikf=0 N=1 Xti=3 Eg=1.11 Cjo=220p M=.5959
+ ? ? ? ? ? ? ? Vj=.75 Fc=.5 Isr=2.035n Nr=2 Bv=3.3 Ibv=45.862m Nbv=3.0477
+ ? ? ? ? ? ? ? Ibvl=29.831m Nbvl=11.606 Tbv1=-636.36u)
* ? ? ? ? ? ? ? Motorola ? ? ? ?pid=1N5226 ? ? ?case=DO-35
* ? ? ? ? ? ? ? 89-9-18 gjg
* ? ? ? ? ? ? ? Vz = 3.3 @ 20mA, Zz = 310 @ 1mA, Zz = 68 @ 5mA, Zz = 19 @ 20mA
?
I thought I found a 1N4572 model in our Files, but alas it was not.? I did not find the 1N5241 model but LTspice comes with one for 11.0 V and others nearby.??I did not find 2N3791 in our Files.
?
Andy
?
?
|
The first step is to search the groups
archives from the web site Files page. Then ask the
manufacturer, found by a web search - STI in the case of the
1N4572, Microchip for 1N5226, etc.
On 2025-02-03 21:01, Ivan via groups.io
wrote:
Been looking for some components here, there and everywhere,
and I am having a hard time finding them. I'm looking for 3
zeners and a power transistor.
?
Zeners:
1N4572A 6.4V Zener
1N5226B 3.3V Zener
1N5241 11V Zener
?
Transistor:
2N3791
?
Any help would be appreciated. I am totally down with trying
to model it myself via their datasheets, and have some idea of
how to do that but, I've never attempted that before so, any
push in that direction would help too. It might help if I could
find equivalents that may be in the LTSpice library that I could
use or, equivalent enough that I can change some of the it's
values in order to create what I need. Of course, I'm checking
YT for help in these department but, if there's a model out
there, it would be a lot easier. I did find one text doc that is
supposed to be a library of models that includes the 1N5226B
but, it's very difficult to see what is what in that file. I
started re-writing / re-organizing it into something that looks
like a library of models but, don't know if it'll amount to
anything. I was planning on uploading it here and see what you
guys make of it. Let me know.
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
On Mon, Feb 3, 2025 at 04:01 PM, Ivan wrote:
I did find one text doc that is supposed to be a library of models that includes the 1N5226B but, it's very difficult to see what is what in that file.
Beware.? There is at least one long list of library parts, which I've seen uploaded in this group a few times, but they are not the models.? It is just a list of the parts that you could get, if you installed a separate program or purchased someone's library.? I don't know if this is what you saw, but it might be.
?
On the other hand, it could be a library of models.? If it seems difficult to read, it might be a text file formatting thing.? Some text files use CR/LF characters between lines, some use just CR or just LF, and some use LF/CR.? Windows's Notepad can't display all of them correctly.? Try another text editing program.
?
Another possibility is that it is an encrypted file, but that is less likely.
?
Andy
?
|
Wow! Have you seen the price of 2N3791s? They haven't been made for
decades. Why are you using them?
--
Regards,
Tony
On 03/02/2025 22:01, Ivan via groups.io
wrote:
toggle quoted message
Show quoted text
Been looking for some components here, there and everywhere,
and I am having a hard time finding them. I'm looking for 3
zeners and a power transistor.
?
Zeners:
1N4572A 6.4V Zener
1N5226B 3.3V Zener
1N5241 11V Zener
?
Transistor:
2N3791
?
Any help would be appreciated. I am totally down with trying
to model it myself via their datasheets, and have some idea of
how to do that but, I've never attempted that before so, any
push in that direction would help too. It might help if I could
find equivalents that may be in the LTSpice library that I could
use or, equivalent enough that I can change some of the it's
values in order to create what I need. Of course, I'm checking
YT for help in these department but, if there's a model out
there, it would be a lot easier. I did find one text doc that is
supposed to be a library of models that includes the 1N5226B
but, it's very difficult to see what is what in that file. I
started re-writing / re-organizing it into something that looks
like a library of models but, don't know if it'll amount to
anything. I was planning on uploading it here and see what you
guys make of it. Let me know.
|
Ivan, when you said you had already looked here, there, and everywhere, I assume you searched the Internet for these parts, and found their webpages from the manufacturers that make them.
?
Most (not all) manufacturers have SPICE models for simple parts like diodes and zeners.? But it can sometimes be challenging to find them from their websites.? If you found their website but there is no sign of a SPICE model, I advise you to look more closely.? Sometimes it is a challenge to find them.
?
Andy
?
|
Old Hi-Fi?
On 2025-02-03 21:56, Tony Casey wrote:
Wow! Have you seen the price of 2N3791s? They haven't been made
for decades. Why are you using them?
--
Regards,
Tony
On 03/02/2025 22:01, Ivan via
groups.io wrote:
Been looking for some components here, there and
everywhere, and I am having a hard time finding them. I'm
looking for 3 zeners and a power transistor.
?
Zeners:
1N4572A 6.4V Zener
1N5226B 3.3V Zener
1N5241 11V Zener
?
Transistor:
2N3791
?
Any help would be appreciated. I am totally down with
trying to model it myself via their datasheets, and have some
idea of how to do that but, I've never attempted that before
so, any push in that direction would help too. It might help
if I could find equivalents that may be in the LTSpice library
that I could use or, equivalent enough that I can change some
of the it's values in order to create what I need. Of course,
I'm checking YT for help in these department but, if there's a
model out there, it would be a lot easier. I did find one text
doc that is supposed to be a library of models that includes
the 1N5226B but, it's very difficult to see what is what in
that file. I started re-writing / re-organizing it into
something that looks like a library of models but, don't know
if it'll amount to anything. I was planning on uploading it
here and see what you guys make of it. Let me know.
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
On Mon, Feb 3, 2025 at 04:57 PM, Tony Casey wrote:
Wow! Have you seen the price of 2N3791s? They haven't been made for decades. Why are you using them?
--
Regards,
Tony
?
I'm actually trying to simulate a device we make at work. I work at a small company and their stuff is old as hell. Lol! The company has been around for 40 or so years so, a lot of the devices were designed with really old components and..., they've never been updated. In my department specifically, we still used DOS programs up until our testing rig died about two years ago. Lol! Every so often something goes obsolete and the department head has to scramble to find a replacement. Unfortunately, most of our stuff has to meet government standards so, changing one component to another is a real PITA and, time consuming. Worse still, they fired their last engineer here about two years ago so, no one actually knows how any of our products really work at the deepest component level. Don't know how the company is staying afloat. In any case, I am trying to up my game some to eventually ask for more money. :) We're mostly in production mode all the time but, quite often we also have to troubleshoot and fix stuff. Most are easy fixes but, this one device has been a mystery to us all. Not completely but, enough where we just don't know what to make of certain anomalies when they pop up. Either way, if I could simulate this device, I think it'll really help me understand some things better.
|
On Mon, Feb 3, 2025 at 04:41 PM, Andy I wrote:
Ivan,
?
When looking for models, consider these:
- Search the Internet (part vendor sites) for "equivalent" parts.
- Go to the group's Files section, and type in the model number in the Search box in the upper right corner.
I searched the vendor sites but have so far come up empty. I will try again. I did also search on this site but, nothing came up for any of these parts. Finally, I tried perusing that long ass set of links from the old yahoo group but, there's just way too many links to go through. I got maybe a quarter way through before I gave up.
- Consider omitting the suffix (A or B) if you understand what it does.? Often it does not matter.
I can check the data sheets to see if there are any differences but, even if it does, and I do find a model file like the one you posted below, can't I just change the one or two parameters that may be different in the datasheets and then, after updating the model file, save the model file under a new model name?
- Find a similar zener from among LTspice's built-in diodes.? I recommend this way:
- Start with a Zener symbol, right-click on the symbol, then click "Pick New Diode".
- Now click "Vbrkdn[V]" at the top, THEN click "Type" at the top.? Now they will be sorted into diode types, followed by breakdown voltage.
- Scroll down until you find the Zeners.? Then look for the same or a similar voltage.
- Try to find a diode with similar power ratings.
- ?
I will try that
- Find a similar zener by checking manufacturer's part selector guides; they often list "equivalent" or "replacement" parts.
Tried that but, I will try again.
- For a zener, if you plan to use it only in breakdown, many of the SPICE characteristics won't matter, and you can probably get away with a very crude or approximate model.
That's what I'm figuring.
I found a 1N5226 (no B) model in our Files. It says its source was Motorola:
* 1N5226 ? ?3.3 Volt ?5% ?W zener diode
.model D1N5226 ?D(Is=31.47f Rs=9.494 Ikf=0 N=1 Xti=3 Eg=1.11 Cjo=220p M=.5959
+ ? ? ? ? ? ? ? Vj=.75 Fc=.5 Isr=2.035n Nr=2 Bv=3.3 Ibv=45.862m Nbv=3.0477
+ ? ? ? ? ? ? ? Ibvl=29.831m Nbvl=11.606 Tbv1=-636.36u)
* ? ? ? ? ? ? ? Motorola ? ? ? ?pid=1N5226 ? ? ?case=DO-35
* ? ? ? ? ? ? ? 89-9-18 gjg
* ? ? ? ? ? ? ? Vz = 3.3 @ 20mA, Zz = 310 @ 1mA, Zz = 68 @ 5mA, Zz = 19 @ 20mA
?
This looks like a PSpice file, no? From what I understand, LTSpice can read them no problem, right? Or, do I have to remove that first D in the name, for example, in order for LTSpice to recognize it? I'm assuming I just copy and paste this into a text file and name it 1N5226.lib or .mod or something and try it out, no? If it works, I can just add it to my user.dio file.
I thought I found a 1N4572 model in our Files, but alas it was not.? I did not find the 1N5241 model but LTspice comes with one for 11.0 V and others nearby.??I did not find 2N3791 in our Files.
?
Yeah. It's been a bitch to find these files. Either way, thanks again for all your help.
|
On Mon, Feb 3, 2025 at 04:46 PM, John Woodgate wrote:
The first step is to search the groups archives from the web site Files page. Then ask the manufacturer, found by a web search - STI in the case of the 1N4572, Microchip for 1N5226, etc.
I tried the group archives a couple of different ways but was unsuccessful. As far as STI, what is that an acronym for again? As far as Microchip, their site has not been helpful so far. Got the data sheet but, can't find a spice file. Tried it again just now and, still no spice file. As with most data sheets, I believe I have most of what I need to model my own if I have to. Thoughts? In the meantime, let me know about STI.
|
On Mon, Feb 3, 2025 at 04:54 PM, Andy I wrote:
On Mon, Feb 3, 2025 at 04:01 PM, Ivan wrote:
I did find one text doc that is supposed to be a library of models that includes the 1N5226B but, it's very difficult to see what is what in that file.
Beware.? There is at least one long list of library parts, which I've seen uploaded in this group a few times, but they are not the models.? It is just a list of the parts that you could get, if you installed a separate program or purchased someone's library.? I don't know if this is what you saw, but it might be.
It wasn't anything like that.
On the other hand, it could be a library of models.? If it seems difficult to read, it might be a text file formatting thing.? Some text files use CR/LF characters between lines, some use just CR or just LF, and some use LF/CR.? Windows's Notepad can't display all of them correctly.? Try another text editing program.
?
It was just a long string of words without any separation. I copied and pasted it off some posting from a link on some spice model site.
Another possibility is that it is an encrypted file, but that is less likely.
?
It wasn't an olb file. I have one of them from OnSemi or, OrCad or something. Sucks that I can't hack into that one. :) This file is in plain English. It definitely wasn't formatted hence, why I tried to bang it into something that looks like a library. Mainly, I'm trying to correlate what they seem to be describing as the parameters of the device, with the section where the parameters seem to be listed, if that makes any sense. I can copy and paste it into my next response. It isn't that long. Let me know.
|
On Mon, Feb 3, 2025 at 05:46 PM, John Woodgate wrote:
Old Hi-Fi?
?
I wish. I'm a musician. Been through many tube guitar amps so I love them old radio engineers handbooks and the sort but alas. No. We make gas sensors to detect dangerous gases in industrial settings. Hence, the need for government standards.
?
|
On Mon, Feb 3, 2025 at 07:40 PM, Ivan wrote:
I searched the vendor sites but have so far come up empty. I will try again. I did also search on this site but, nothing came up for any of these parts.
I think it is critical to omit the suffix letters when searching.? I do not claim there is no difference between a 1N4572 and a 1N4572A, but sometimes the only difference is either (1) it is in a different package, or (2) the "A" or "B" version is guaranteed to meet its specs over a wider or narrower temperature range.
?
When John Woodgate said he found two of them on the Internet, that gives me hope, and says you probably missed them.
?
I can check the data sheets to see if there are any differences but, even if it does, and I do find a model file like the one you posted below, can't I just change the one or two parameters that may be different in the datasheets and then, after updating the model file, save the model file under a new model name?
Sure.
?
Be aware that SPICE model parameters usually do not correspond directly to datasheet specs.
?
Anyway, even if a 1N4572 and a 1N4572A actually are different, I would not expect their differences to be as much as between a 1N4572A and a 1N5226B.? ?Chances are very good that the same SPICE model works equally well for both.? No SPICE model matches 100% (and no two samples match each other 100%), but I would kind of expect that one SPICE model is equally close to both 1N4572A and 1N4572.
* 1N5226 ? ?3.3 Volt ?5% ?W zener diode
.model D1N5226 ?D(Is=31.47f Rs=9.494 Ikf=0 N=1 Xti=3 Eg=1.11 Cjo=220p M=.5959
+ ? ? ? ? ? ? ? Vj=.75 Fc=.5 Isr=2.035n Nr=2 Bv=3.3 Ibv=45.862m Nbv=3.0477
+ ? ? ? ? ? ? ? Ibvl=29.831m Nbvl=11.606 Tbv1=-636.36u)
* ? ? ? ? ? ? ? Motorola ? ? ? ?pid=1N5226 ? ? ?case=DO-35
* ? ? ? ? ? ? ? 89-9-18 gjg
* ? ? ? ? ? ? ? Vz = 3.3 @ 20mA, Zz = 310 @ 1mA, Zz = 68 @ 5mA, Zz = 19 @ 20mA
?
This looks like a PSpice file, no?
Well, yes, and no.? It is a SPICE model.? That makes it a PSpice model, and an HSPICE model, and an LTspice model, and everybody else that makes SPICE programs.
?
From what I understand, LTSpice can read them no problem, right?
Yes.? LTspice is SPICE and it reads SPICE models.? Every parameter above is understood and used by LTspice.? They are SPICE diode model parameters, after all.
?
Notice that the last 3 lines are comment lines (ignored by SPICE and LTspice and PSpice and ...).
Or, do I have to remove that first D in the name, for example, in order for LTSpice to recognize it?
Keep it or delete it, whatever you choose.? LTspice recognizes alphanumeric names.? Old versions of SPICE (and programs derived from it) required a letter as the first character, which is why you occasionally find model names like that.? But LTspice doesn't care.
?
I'm assuming I just copy and paste this into a text file and name it 1N5226.lib or .mod or something and try it out, no?
Pretty much, yes.? To just "try it out", indeed even to use it normally, it does not need to be in a separate file.? You could put it on the schematic itself, as a SPICE Directive.
?
If instead you save it to a separate text file, remember to include the file, with a ".inc" or ".lib" statement.
?
Andy
?
|
On Mon, Feb 3, 2025 at 08:00 PM, Ivan wrote:
As far as STI, what is that an acronym for again?
I think that is the name of a company.? I wonder if John meant STM (STMicroelectronics)?? (There is an STI that makes thermocouples.)?
CORRECTION:? The company name John refers to is ST, also known as ST Micro or ST Microelectronics NV.? They sometimes use the abbreviation STM and sometimes just ST, as in their website presence, and perhaps STI although I did not find that one.? Their website is .
?
I am not getting STI from Google searches of that zener.? But I did get a hit from Microsemi ().? I do not see a link to or mention of a SPICE model on that page but I did not try looking harder.? When that happens, sometimes one needs to contact the manufacturer and ask if they have one.? I think that is probably not needed now.
?
Manufacturers might give you very little information about old or rarely used parts.
?
FYI, Microsemi's datasheet says the difference between the 1N4572 and 1N4572A is the temperature range.? The "A" version is spec'd from -55 to +100 C (Miliitary Industrial or Military grade), whereas the non-A is from 0 to +75 C only (Consumer Commercial grade).? Same device, but different guarantees --> higher price.
?
Andy
?
|
On Mon, Feb 3, 2025 at 08:11 PM, Ivan wrote:
It was just a long string of words without any separation. I copied and pasted it off some posting from a link on some spice model site.
Not even spaces?? Wow.
?
Often a text file displays incorrectly in Notepad because it appears to be missing linefeeds, turning it into one run-on sentence or long paragraph, but the spaces between words and fields would still be there.? It doesn't really matter, but can you make out words?
?
It wasn't an olb file.
I did not mean that, FYI.? AFAIK, .olb files are not encrypted; they are binary.? I believe they are symbol files, giving them similar functionality as LTspice's .asy files.? PSpice uses .olb files.? LTspice does not.? Since they are symbol files, they are not the SPICE model.? They probably describe the shape and appearance of the object on your schematics.
?
Andy
?
?
|
I don't remember if I replied to this already:
?
I tried the group archives a couple of different ways but was unsuccessful.
The key was to strip off the "A" or "B" suffix.
?
Searching for "1N5226B" fails.
Searching for "1N5226" succeeds.
?
The 1N5226 is the more common diode, for most of us who don't build for the U.S. military.? The 1N5226B (supposedly) goes through more thorough testing and more steps and documentation, jacking up its price.? It is probably the same exact die coming out of the furnace.
?
Andy
?
|
FYI -
?
I made some changes to one of my previous replies, which mostly do not affect this discussion, but I want to be more correct about them.
?
In most common usage, -55 to +100 C would be somewhere between Industrial and Military Grade.? 0 to +75 C would be Commercial grade.
?
Andy
?
|
Hi Ivan,
?
I've uploaded a zip file - some-zener-models.zip - with 2 files in it. The Cordell text file I might have downloaded from here, can't remember.
?
The 1N5241B is in both files. There may be some equivalents you can use.
?
--
--
Regards,
Abes
|
Which country are you in? I know of a British
supply of the power transistor at a very low price,
comparatively, but not for export.
On 2025-02-04 00:23, Ivan via groups.io
wrote:
On Mon, Feb 3, 2025 at 04:57 PM, Tony Casey wrote:
Wow! Have you seen the price of 2N3791s? They
haven't been made for decades. Why are you using them?
--
Regards,
Tony
?
I'm actually trying to simulate a device we make at work. I work
at a small company and their stuff is old as hell. Lol! The
company has been around for 40 or so years so, a lot of the
devices were designed with really old components and..., they've
never been updated. In my department specifically, we still used
DOS programs up until our testing rig died about two years ago.
Lol! Every so often something goes obsolete and the department
head has to scramble to find a replacement. Unfortunately, most
of our stuff has to meet government standards so, changing one
component to another is a real PITA and, time consuming. Worse
still, they fired their last engineer here about two years ago
so, no one actually knows how any of our products really work at
the deepest component level. Don't know how the company is
staying afloat. In any case, I am trying to up my game some to
eventually ask for more money. :) We're mostly in production
mode all the time but, quite often we also have to troubleshoot
and fix stuff. Most are easy fixes but, this one device has been
a mystery to us all. Not completely but, enough where we just
don't know what to make of certain anomalies when they pop up.
Either way, if I could simulate this device, I think it'll
really help me understand some things better.
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
On 2025-02-04 01:00, Ivan via groups.io
wrote:
On Mon, Feb 3, 2025 at 04:46 PM, John Woodgate wrote:
The first step is to
search the groups archives from the web site Files page.
Then ask the manufacturer, found by a web search - STI in
the case of the 1N4572, Microchip for 1N5226, etc.
I tried the group archives a couple of different ways but was
unsuccessful. As far as STI, what is that an acronym for again?
As far as Microchip, their site has not been helpful so far. Got
the data sheet but, can't find a spice file. Tried it again just
now and, still no spice file. As with most data sheets, I
believe I have most of what I need to model my own if I have to.
Thoughts? In the meantime, let me know about STI.
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
John Woodgate
Tony Casey