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Old 11th March 2012, 11:52 PM   #3281
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I was a personal colleague of Owsley (Bear), up until his recent death (in a road accident). I generated a great many 'breakthroughs' because of Acid.
Actually, what I was most interested in finding is how electricity flows in a wire. I still don't know much.
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Old 12th March 2012, 12:12 AM   #3282
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Quote:
Originally Posted by bcarso View Post
No need to apologize. I will continue to strive for historical accuracy, duly mindful that once a name gets associated with a circuit, or when a phrase is imprecise but understood by most anyway (like "linear beta" used when "constant beta" is meant), change is nearly impossible.

And I argued along fundamental principles to no avail with the particular individual.

And yes, the patent system is absurdly dysfunctional and has been for quite a while. And patent protection is useless to the small inventor anyway. I may have mentioned a recent one, being highly touted as a breakthrough by its co-inventor, a power amplifier supposedly that we've all been impatiently awaiting. The only problem is it doesn't work very well, and it's prior art dating back at least to 1991. Another amplifier designer who's been mentioned in here said "the primary claims are suitable as a wrapper for dead fish".
I also come from another side of the fence, where patents meant nothing, so my ignorance in the history of names causes sometimes sour jokes from JC side, like "I know Wavebourn you've invented everything", when working on some design I am coming to some topology that was named and stamped before by somebody else... So what?
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Old 12th March 2012, 12:36 AM   #3283
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John & good company,
Please, I really do appreciate the help. That there are different views is also quite informative. From a handful of names in this forum, I can see several hundred years experience. I have more than considerable respect for that. Those that do, rather than those who say they do.

I will try and track down an original book, but they are not any help on the newer parts. If the newer part has no data, what am I to compare the older fully documented part to? I checked our local library today and it has little more than empty shelves, a few pop culture books and internet terminals. It would be easier to get into the UCB library as at least I know where to park there. Maryland? Forget it. If I remember, (circa 1980) the Motorola and TI books were the most extensive.

This: http://www.amazon.com/Small-Signal-T...508715&sr=8-23
is not what I remember. These were the short version. I remember the real book was about three inches thick. The above is what is available this week.

For choosing parts to use today, they are not much help as almost nothing is still being made and with the experience I had with On-Semi, what is being made is not at all like the book says. Not the 2N2222 or 2N5551's I bought for sure. When I look at what parts were chosen for commercial products, recognizing the trade-offs necessary for manufacturing, I find what looks like great choices, and almost none of them are still being produced.

I am back at not knowing what to look for. Within SOA, what graphs should I be looking at that would suggest one part will perform in a more linear manner for which parameters or where should I use a given part to let it behave to the best of its ability? They all behave like several bad caps, vary C, vary leakage, vary distortion, vary gain, bandwidth and everything else, all with changes of voltage, current and temp. Got it. Keeping if from blowing up is just the first step. Now, where should I be looking for predictable in-circuit behavior? I am coming to the table after desert was served and sitting in on the conclusion of the entire days conversation. It is not in context yet.
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Old 12th March 2012, 02:09 AM   #3284
bcarso is offline bcarso  United States
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National Semi databook.jpg

National Semi databook process 23.jpg

National Semi databook process 26 pg 2.jpg

National Semi databook process 26 pg 3.jpgThis is a National Semi databook which actually had useful information. Unfortunately the parts were typically mediocre. They stopped giving anything like this much detail a while later, I suspect because of liability concerns (I took your curves and trusted them and then my arcilator blew up and I'm suing you!).

The pages I picked to show are for a process from which 2N3904 parts were selected, a garden-variety small-signal device that I used for years until discovering way-better things.

Note my pencil markings, at times trying to extrapolate the curves

Brad

Last edited by bcarso; 12th March 2012 at 02:11 AM. Reason: oops it ate my images!
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Old 12th March 2012, 02:13 AM   #3285
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Quote:
Originally Posted by bcarso View Post
<snip>
I will continue to strive for historical accuracy,
<snip>
And yes, the patent system is absurdly dysfunctional and has been for quite a while.
<snip>
Dear Brad and all,

Speaking of historical accuracy...
I joined this forum in the process of looking for any mention of US Patent 5,155,449 here.
When I first saw it, my jaws dropped. My first reaction was - how dare someone to patent a circuit that I considered to be a "common knowledge" up until that moment. I am sure, I've seen this topology way before 1992.
Anyone care to comment?

Best,
Attached Images
File Type: jpg US5155449.jpg (230.4 KB, 92 views)
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Old 12th March 2012, 02:14 AM   #3286
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Looking at another schematic from a respected high end company whom I shalt not name, seems to fall into the less is more camp. Anyway, the IPS ccs is a very standard single transistor/red LED, but it is paralleled with a pair of 1N4148's. LED datasheets are all about light and power, nothing about speed or noise. Are they slow and these diodes are a clamp?

Is there some irony that some of the amps with the fewest components are the most expensive?
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Old 12th March 2012, 02:19 AM   #3287
tvrgeek is offline tvrgeek  United States
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Quote:
Originally Posted by bcarso View Post
Attachment 271321

Attachment 271322

Attachment 271323

Attachment 271324This is a National Semi databook which actually had useful information. Unfortunately the parts were typically mediocre. They stopped giving anything like this much detail a while later, I suspect because of liability concerns (I took your curves and trusted them and then my arcilator blew up and I'm suing you!).

The pages I picked to show are for a process from which 2N3904 parts were selected, a garden-variety small-signal device that I used for years until discovering way-better things.

Note my pencil markings, at times trying to extrapolate the curves

Brad
Now that comment makes sense. Liability. I know the folks designing them know all about them or they would not have made it into production.
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Old 12th March 2012, 02:24 AM   #3288
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The patent is a version of the WHITE follower shown in the MIT series from WW2.
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Old 12th March 2012, 02:32 AM   #3289
bcarso is offline bcarso  United States
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Quote:
Originally Posted by elektroj View Post
Dear Brad and all,

Speaking of historical accuracy...
I joined this forum in the process of looking for any mention of US Patent 5,155,449 here.
When I first saw it, my jaws dropped. My first reaction was - how dare someone to patent a circuit that I considered to be a "common knowledge" up until that moment. I am sure, I've seen this topology way before 1992.
Anyone care to comment?

Best,
Oh Brother! But then, where did I first see it?

As Thorsten points out, so much of this stuff is basic principles stuff. And it seems like each discipline that uses electronics has to rediscover topologies that have long existed in other specialized areas. How many nuclear science folk read (past tense) the Radiotron Designer's Handbook? I know that in astronomy there were very few that knew very much about electronics (and as as the saying goes, In the land of the blind, the one-eyed man is King).

I struggled with charge preamps, initially vidicon preamps, based on mistaken noise theory for months. A pair at Princeton (horrors! even Princeton) put forth a theory of JFET noise, as part of their overall paper about their vidicon system, that attributed voltage noise to shot noise in the channel. WRONG! It got published in a fancy Academic Press book.

There was also a number given for the performance, which changed in the first digit in another publication of more-or-less the same paper (intentional coverup or an actual typo?). Finally I started to peruse the nuclear science literature and found them to be the masters of charge preamps. I had a difficult time convincing people in the department that the two Princeton guys were wrong. The worst part is, their analysis led to a selection criterion for JFET parameters that was wrong as well.


Brad
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Old 12th March 2012, 02:52 AM   #3290
bcarso is offline bcarso  United States
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Quote:
Originally Posted by john curl View Post
The patent is a version of the WHITE follower shown in the MIT series from WW2.
Yep. This link mentions the date as 1943 Who invented the Mu Follower?

So that must be in Valley and Wallman?

And again, a very simple and obvious extension to FETs by the authors. But it was enough for USPTO

Brad
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