Larkin, Here's mine...

What he might have believed is that if the product really did take off, economies of scale might have cut the price enough to make the product viable.

The rule of thumb is that if you can increase the volume of production by a factor of ten, you can halve the unit cost of manufacturing the product. The catch is that you rarely know how you are going to do it in advance, and if you've established the market, somebody else may have the bright idea that lets them halve the unit cost of production.

The Germans did it with photovoltaic solar cells, but the Chinese did it again a few years later, leaving the Germans with a lot of plant for making solar cells that couldn't build them at a competitive price.

And you can learn that in psychology 101?

If you want to make things happen, you are always going to step on a few toes. The first rule of industrial diplomacy is "don't rock the boat". Of course, if nobody rocks the boat, your products become over- price and obsolescent and you go bust

But reading a book is a lot cheaper, and if you figure in repair time, much quicker.

My first year text-books were mostly American publications in exactly that style, and they were uniformly useless. The second and third year texts were thicker, duller and much more useful. I kept most of them. I didn't consult them more than once per decade, but I knew exactly where to look in them for the information I needed

c

Mine got borrowed by people taking the courses in subsequent years. I didn't bother borrowing anybody else's. From the questions that they were asking me, I knew that they wouldn't have been helpful. When I was working as a demonstrator in undergraduate practical courses as a graduate student, I got exposed to copied course work - groups of people all making the same mistake. Curiously, the people who got the stuff right tended express themselves in different words (one from another), or at least had enough sense not to copy the text they'd borrowed word-for-word.

I'd call that pre-exam cramming. I'd spend the last day before the exam doing old exam papers, trying to get a feel for the stuff I might not have prepared as well as I might, and getting a feel for how much I'd have time to write. It didn't always work. Once I got mouse- trapped by a question where I knew way too much, and found myself only half-way through my answer when time ran out. I had had the sense to answer all the other questions first.

But it wasn't what I was talking about. I was referring to episodes in our post-education careers when a problem comes up that needs stuff that was taught in University courses, but rarely comprehended - Laplace transforms come to mind. You then have to cram he subject well enough to be able to use the technique.

--
Bill Sloman, Sydney
Reply to
Bill Sloman
Loading thread data ...

)

At job interviews at Cambridge UK I'd run into people who'd been through the - heavily mathematical - Cambridge engineering course, and get asked questions that presupposed familiarity with particular mathematical skills. I'd respond that I hadn't - as yet - found the necessity to master that particular approach, and watch their eyes glaze over.

The besetting sin of Cambridge graduates of that period was their conviction that they were very bright and that nobody who hadn't been accepted by Cambridge to do an undergraduate degree could possibly be as bright. Cambridge was in a position to be very selective about the people they selected as undergraduates, but the selection was based largely on exam results, and certainly didn't get every bright kid in the UK. The best of the Cambridge and Oxford graduates were very bright indeed, and some of them were bright enough to be aware that Oxbridge wasn't the only source of clever people, but there were a lot who had a less perfect grasp of reality.

--
Bill Sloman, Sydney
Reply to
Bill Sloman

*You* are the one being an idiot in public. Don't blame me.

Why don't you google things that you don't recognize, and maybe learn something, instead of saying stuff that everybody laughs at?

formatting link

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

I was intentionally being pedantic, not guessing, so that you could see the quantitative approach and correct any errors, if any.

Jon

Reply to
Jon Kirwan

Agreed. You would probably never hire anyone like me.

I had a simple test for the techs and engineers that I hired. I would excavate a PC board from my desk, and ask the applicant to identify and describe the purpose of as many parts as possible. No schematics. The idea was to gauge their experience with the common components. Since I was usually hiring marginal techs and starting engineers, 50% recognition was considered quite good. I would then make some corrections, describe the board in detail, fill in the blanks, and identify the remaining parts.

Next, I would give the applicant a quick tour of the lab, production line, test line, QA, shipping, and cafeteria with emphasis on what the company was doing. We would then return to my office, where I would dig out the same PCB and ask exactly the same question. If they were paying attention, their recognition score would improve. If the score was about the same as before, they were either not paying attention, a slow learner, or in shock. Moral: Paying attention pays.

Looking at the applicants approach doesn't always work. I interviewed at a local company where I was shown a schematic and PCB of one of their products and asked what I thought of the design. After a cursory inspection, I declared the product to have too many adjustments, used too many stages, had some layout problems, and was lacking in production test and troubleshooting aids. I then proceeded to outline what changes I would recommend. I was too involved in scribbling on the schematic to notice the managers reaction. Later, after personnel asked me what I had done to provoke the anger of the manager, I discovered that it was his design, and that did not take kindly to criticism. Moral: The interview works both ways. In this case, the employer failed the interview.

I once interviewed at a small company that tested me with their problem of the day. They showed me an RF power amplifier schematic that was delivering wildly variable performance in production, and asked what changes I would make to improve things. I suspected that if I were hired, this would be my initial project. I asked to see the PCB on its heat sink. The problem was obvious... lousy layout and regeneration. I recommended a new PCB layout, but that would bring production to a halt. So, I suggested some marginal band-aids, such as additional grounds using finger stock, a change in ferrite material, and a better choice of bypass caps. This was judged to be the "wrong approach". They hired a friend, who was presented with the same problem, played with various band-aids for a few weeks, and gave up. We spent an evening reworking the power amp layout, which eventually worked as expected. Moral: Don't try to 2nd guess what the interviewer wants to hear.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

ote:

tems,

ysics.

So, how come most of the current engineering jobs are for software engineers rather than hardware types? There doesn't seem to be much unemployment for programmers. Eventually, computers and robots will replace all the jobs, and everybody can retire.

-Bill

Reply to
Bill Bowden

The reason that Thompson is so obsessed with Tulane is that he *knows* that I had a whole lot more fun in New Orleans, which was and is a hoot-and-a-half, than he had in Boston, which he hated.

And he knows that, while he was peeping at the girls' dorm with a telescope at night, I was sneaking *into* the girls' dorm at night.

Bugs him, it does.

And for the record, the guys who flunked my emitter-follower test were mostly from Silicon Valley.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

Well, maybe the owners of the robots will be able to retire. Everyone else will be SOL.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward" 
speff@interlog.com             Info for manufacturers: http://www.trexon.com 
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Reply to
Spehro Pefhany

Systems,

physics.

Because

a) Software Engineering is distinctly different from Computer Science

and

b) Lots of "software engineers" don't have degrees in any programming discipline. Anybody can learn to hack Ruby or F#.

There doesn't seem to be much

There soon will be. There are almost 700,000 iPad apps now, and we really don't need a million. Finite pool of money meets infinity of ratholes.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

Clueless Baer sez: ASS-u-ME-ing silicon, Vout approximately (Vdd/2+0.6V); i forgot the TC of a silicon transistor.

Reply to
Robert Baer

Try again >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

You sort of go round the circuit in a circle starting at the upper left.

The left hand side is perfectly symmetrical, and unloaded (beta=infinity). Thus the emitter of the upper left transistor is at exactly VDD/2, always.

Because we have perfect matching and VAF=infinity (no Early effect), the bottom right transistor's collector current is exactly the same as the current in the LH string. Because beta=infinity, that means the upper right transistor's is as well. Therefore the upper right's emitter is at exactly the same voltage as the upper left's, i.e. VDD/2 with zero tempco.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 USA 
+1 845 480 2058 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

Hey, five for one!

Is that a record?

[...]
--

John Devereux
Reply to
John Devereux

Pretty good, but not a record! IIRC it was 8 or 9. Might have been Larkin or KRW that bagged it, but not sure...

Reply to
JW

He muat have a hotkey programmed to macro-out his favorite word, save typing time.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

Precisely. I use such "tricks" IRL (in real life) all the time to ensure matching and tracking in custom chip designs. (Matching on a monolithic chip is very good.) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

I'm not so sure. Systematic thinking always catches my attention.

I've done that more times than I can count. Now I ask, "Nice looking! Who did the design?" THEN I put my foot in mouth ;-)

Yep. Happens all the time. I also sometimes get seriously under-bid. A year or so later I'm called in to fix the mess... now at a premium, of course >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

For a medium fast and extremely precise photodiode circuit, I'm using a four-transistor mirror (the switcheroo version of the Wilson with zero base current error to leading order), with a loop wrapped around it to make its input impedance very very low, while preserving accurate mirroring. (It uses an HFA3128 PNP array, a 9-GHz NPN emitter follower driving the top, and a SiGe:C NPN sensing the input voltage swing. Works great.)

It's quite an interesting circuit--it has four nested feedback loops with a total of six transistors, four of which are matched.

(There are two diode connected PNPs, which are the world's simplest feedback amp, the current-mirroring loop, and the input nulling loop, totalling four.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

I've been known to make one-quadrant multipliers from weirdly-configured mirrors ;-) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

Nah, the record is 9, IIRC, but my personal best is 7.

Reply to
krw

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.