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#141 | |
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diyAudio Member
Join Date: Feb 2001
Location: illinois
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What I see here reminds me of my life as college undergrad. I had some fantastic EE professors who saw potential in me and stuck their foot in my behind whenever I performed at less than their expectation of my capabilities. I didn't appreciate it until I was a junior and really began to see the fruits of their efforts and what it would mean for my future.
I see some of the "noisy" people here (like Fred) as doing the same thing. For this stuff, you understand it by fighting to wrap your brain around it. Sometimes it's more of a struggle than at other times. Some of us have learned - reading helps.... A lot.... As Nike says, "just do it" mlloyd1 (who puts his foot down whenever the wife says "why are you keeping those old The Audio Amateur magazines?") (and who also: 1. waves "hi" to Walt, 2. still enjoys the super regs says (Thanks Walt!) 3. can personally vouch for him being a VERY helpful and VERY knowledgable guy for much more than super regulators! Quote:
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#142 |
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diyAudio Member
Join Date: Jul 2003
Location: berkeley ca
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Actually, you folks act kind of silly, but please don't take offense. Weeks ago, I invited Walt Jung over to this website. Please, let him want to join in and teach us a thing or two. ;-) . When 'we' contribute to magazines, we usually expect people to use our designs, but we like to get credit, when it comes up at a place where it can be put in print.
I don't know the legal aspects of copyright, but I would love it, if I could sue anyone who has copied and built what I have published in the past. Who would need patents then? |
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#143 | |
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diyAudio Member
Join Date: Aug 2003
Location: USA
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Quote:
US claiming IP on feedback regulators? Why not? For example, see the 1946 MIT Rad Lab series #21, "Electronic Instruments", section 16-6, 'Practical Regulator Design / Precision DC Voltage Supplies', in Fig. 16-27 for example. A tube based feedback regulator with the VR105 reference tube fed from the regulated output. A 6SL7 differential input amplifier is used, with a 6Y6 pass tube. This section was authored by A. Jacobsen and J. V. Holdam, Jr. This clearly predates any solid state/op amp based feedback regulators, which as far as I know came about in the 1960s and 1970s. It is very interesting to see just how much the early technology had been optimized. The circuit in question had an output impedance of 0.8 ohms, and a regulation of 0.05%. But these were serious times indeed, there was a war ongoing. Don't look for this work online (except perhaps a purchase via www.abebooks.com , where I got my copy). Not everything of value exists on the internet, and never will. Some very good stuff still takes some hard work and digging. When one goes through this process, the knowledge gained and subsequently absorbed has greater staying power than that which is simply dropped into one's lap. Walt Jung |
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#144 |
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diyAudio Member
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US Inventions
The Silicon Transistor : Texas Instruments The Integrated Circuit: Texas Instruments The Micro Processor: Texas Instruments Of course we did not invent the Saab but we own it.
__________________
Jim W. |
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#145 |
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diyAudio Retiree
Join Date: Oct 2002
Location: Spain or the pueblo of Los Angeles
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"Not everything of value exists on the internet, and never will. Some very good stuff still takes some hard work and digging. When one goes through this process, the knowledge gained and subsequently absorbed has greater staying power than that which is simply dropped into one's lap."
This is why I frequently visit the engineering section of my local used bookstore. I also wore my boss out ordering books in my last telecom job. Someone stole my Horowitz and Hill and I am still furious. I let a copy of Henry Ott's "Noise Reduction Techniques in Electronic Systems" get away from me at the used bookstore because i was stupid enough to think i would pick it up on my next visit. How about a list of your favorite Analog text and articles from beginner to advanced, in a new thread Mr. Jung? I expect you to include a couple of your op amp books of course and I post the titles if you are too modest. A word of warning though, modesty is a rare affliction on this forum, except for Nelson Pass of course, and we expect him to recover sometime in the near future...... |
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#146 |
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diyAudio Member
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This Walt Jung book has been well used and much appreciated. There no longer a front cover, that came and went over 20 years ago. I purchased this book about 1978 and did help me out of many a problem.
Thanks Mr. Jung for all the good ideas.
__________________
Jim W. |
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#147 |
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diyAudio Retiree
Join Date: Oct 2002
Location: Spain or the pueblo of Los Angeles
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I bought it about the same time as you. Mine had 'home made file folder' front and back covers before it completely disintegrated from use! My third edition has plenty of miles on it and my Audio IC Op Amp Applications is shedding pages from the chapter on Equalized Amplifier and Active Filters. This book and a few Spice models saved my butt when designing filters for a telecom answer supervision board. We even got our benchmark test of calling Honolulu for the volcano report to finally work every time!
'Read it to shreds' Fred |
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#148 | |
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diyAudio Member
Join Date: Aug 2003
Location: USA
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Quote:
Hi Jan, many thnx for the well-wishes. As you can see, they have me busy here, talking about the new/old regulators. Hope all is well with you and yours... Walt |
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#149 |
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diyAudio Member
Join Date: Jun 2003
Location: USA
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> we have a number of professionals and advanced amateurs who have a lot of theoretical and practical knowledge to share with us, if they don't mind doing so.
Threads like this, with more noise than information, make such people "mind doing so". After this morass, Walt might decide to stay away from ALL forums. > Some of these people are well reputed designers, which should give them a high credibility All respect to Walt Jung and John Curl: commercial fame should cut little ice. Maybe the "Famous Designer" is just very good at selling so-so products? Maybe he's the front-man for a genius he keeps locked in the cellar? That has happened, a lot. (Actually, my respect for Walt's writings is deep. The OpAmp, Audio, and Filter CookBooks are superbly concise, clear, and as complete as can fit inside covers. Sorry, I know less of Curl's work, except his products are well-regarded.) > for some others we basically only have their own claims of competence. Anybody who boldly claims competence probably wishes he had more. The true guru will sketch-out the path, at a level that the questioner can handle, and let the student explore the landscape with just a few more hints. We who read the guru's words should not ask "who is this guy?", but "does this understanding mesh, in some useful way, with my understanding?" Or to put it more crudely: a BullPoop detector. The teacher can sometimes know less than the student overall, if he has a single insight into something the student is "not getting". If you read through and of Walt's EDN articles, you don't have to know who Walt is. He explains enough that any truly interested reader can understand the concept and work out the details, and decide if the idea is crap or not. Now, Walt happens to be an exceptionally good writer (part talent, but a lot of practice) so he can say in two paragraphs what it might take some of us a whole page to cover. But we can type that page, and let readers decide if the idea is crap or not. There are a number of people here who have thoughts about things just as valid as any Famous Designer. We should discount the person (and any writing difficulty) and look at the idea. > I do want a convincing argument I added emphasis because those two words MUST go together. There is plenty of "argument" in this thread, but I don't see much or any "why" (convincing) about the regulator topology Peranders put before us. In fact I don't see any data or guess-work about start-up time, and only my quickie about dropout behavior. I posted only a "quickie about dropout behavior" because I knew Peranders has the expertise to see the situation himself (a lot faster than he could read through the noise in this thread), and just needed a "poke" to move his thinking. Yes, I am aware that Peranders sells stuff; but I very much doubt he is "getting rich" from selling a few boards and parts. Anybody who has tried that knows that after tooling expense, order-site setup time, and hours of order fulfillment, the nett profit is about ZERO. Peranders basically sells a few to cover the tooling cost of building one for himself. Any notion that we should not help for free just because "he sells" is misguided. And repeatedly refusing to help simply clutters the board. |
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#150 |
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diyAudio Member
Join Date: Jun 2003
Location: USA
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> I do think one should also try to spur them to read up on at least some basic stuff like Ohms and Kirchoffs laws.
This baffles me. WHY would anybody expect any electric thing to work, without the very basic understanding of volts, resistance, and current? OK, you plug in a lamp, or you assemble a kit, without knowing what's really happening. But I see people on forums like this trying to compare different alternatives, or tweak a circuit, when they can't guess "12 volts across 22KΩ". To my thinking, you can't look at circuits unless Ohms Law is "a reflex": you look at 12V and 22K and instantly think "about a half milli Amp". And while I don't consciously invoke Kirchoff too often, any time one wire splits into two it is old Kirchoff who will tell me (again more by reflex than thought) about how much current will flow up each wire. At a more advanced (yet necessary) level: it is reasonable that most transistor workers can't cite Ebbers-Moll (large-signal transistor equations), but I'm shocked how many are not aware of Shockley's Relation (transistor Gm versus Ie). Not by name of course, but you should be aware that any silicon transistor's transconductance can be known just by knowing its current. I can't see how you would design without that information. Shea's Stability Criteria is also good to know, yet oddly only one book seems to mention it. (And none of these seems to pop-up in Google; as Walt says "Not everything of value exists on the internet, and never will." In fact the Internet is a sharp filter: only odd snippets of pre-1995 appear on it.) > people who want to ask questions too embarassing for here are also welcome. Sometimes I like helping them the best. When they seem too embarassed, I remind them: nobody is born knowing this stuff. Not Jung, not Curl, not Borbely, not even Steinmetz. Oh, maybe Tesla had his concept of Ohms Law from birth. But the rest of us have to learn it some time. No embarassment in that. Walt> posting the 3d Ed. "Audio Apps." as a PDF I think that would be good for a lot of people. "Audio" has been out of print so long, and so treasured by its owners, that it is exceptionally hard to get a copy. The First Edition, good on basics but implemented with 1975 devices, now sells for $60+ "very good". I've seen some badmouthing of "Art of Electronics", but maybe that person was put off by its size (and cost) and failure to emphasize the specific audio issues he was interested in. I think it is a great book, and if there weren't a copy in a library 1,000 feet from my office I might own one. FWIW, the 1989 edition is on Amazon for $75 New, various editions and conditions are $30-$100+ on ABE.com Damon> Or you can access >my< library shelf over my bed. So give us your address, we'll all come read on your bed. (My Jung IC CB was on my bedside stack for years; I guess they moved downstairs only so I could try things on the PC.) I said (pages ago): "there is no single novel thing in the Jung Reg. All of it had been done decades before". And I ventured the opinion that Walt would say so too. He later said: "see the 1946 MIT Rad Lab series #21, "Electronic Instruments", section 16-6, 'Practical Regulator Design / Precision DC Voltage Supplies'". I believe the specific feature (reference fed from output) appears even earlier, late 1930s but I would have to skim all my old texts to confirm that. FWIW, transistor regulators were "old hat" by 1960. (Some of the big soft slow Germanium power devices were not good for much else.) John Curl commented about copyright issues: if you think something is novel, a deep literature-search will usually find something similar and much older. (However, copying someone else's -drawing- without permission IS copyright abuse, hence the scan/post far above is food for Walt's lawyers. Laws aside, I agree that the real "sin against knowledge" is posting less than the full story, especially when told by Walt.) |
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