A circuit so stupid, Larkin could've come up with it

You don't rely on device parameters? I suppose it is convenient to only stock a single resistor value.

Are you competing with JT for some sort of jerk award? You seem a little young to be getting senile already.

All the stuff that I design works, usually the first time, and it's manufactured and shipped in volume.

How would you do this?

Or this?

Or this?

John

[snip] [snip]

At least I'm not competing with Al Gore for selling obfuscation.

AND, I'm not ignorant enough to think living in San Fransicko, Californica, is a good thing.

GFY, John, You're getting REALLY boring.

Stop showing us boxes, and start showing schematics that meet good engineering practice. Be prepared to defend them :-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     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     |
             
      The only thing bipartisan in this country is hypocrisy

me

I agree the cited circuit is pretty stupid - why use a billion parts to do a job that you could do with one? Or maybe three, with PWM.

But I don't understand this personal hardon for John. Can you explain that?

Thanks, Rich

I rely on device parameters that I can rely on. This circuit, maybe not so much. But Rds(on) is specified about as well as beta is, wouldn't you say?

I don't stock a single resistor value, but I do find I use an awful lot of

1k, 4.7k and 10k. There's quite a lot you can do with just those three. Hard to do much without other values though.

The last major project I designed worked the first time, requiring only minor adjustments in the control loops. And it spans three (smallish) boards.

None of these products are remarkable. They are all well within the known laws of physics. Possible ways to design them are immediately obvious. Actual implementation would take longer to work out, and the complete design, a few months more.

The only thing that might be impressive about them are the tedious refinements (the kind of thing Tektronix was expert at, making things like your handsome square wave), and repetition in scale, which people find amusing (like those entertaining domino videos), but which is mindless work putting together. 256 input ADC? Sure, that's easy. It takes a lot of op-amps and big board space to hold everything, but each channel is just as boring as the next, just filters and switches and whatnot.

The data processing that brings everything together should be impressive, if not for already being pedestrian today. (It's a sad age when billions of transistors, and their programming, can be considered boring.) Just slap in an FPGA, wave the magic VHDL wand, and there's your bus interface. Microcontrollers, FPGAs -- computers in general, are tedious to make (>1G transistors) and tedious to program (>10k LOC). They are neither hard to make nor difficult to program.

It's too bad all that tedium has to be done by human hands, so much of it could be so easily written automatically. Then, there would actually be time to do impressive things. Too bad the "software design software" required is somewhat more complicated than anything anyone can understand today. If it's true that "software design software" can never design itself, then since humans are software writers, they will certainly never be able to write one.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

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Tim,

Why are you going down this path? I would rather design an easy product that sells in which I have market share , than a hard product that never sells.

I am not saying that Larkins designs are easy or hard, I am saying that if you want to flame someone learn to pick the right things to flame about. Clearly the guy has a company that sells products and employs people. What about that is flameworthy? Seriously, at your age you should be asking the guy questions about his designs and trying to learn something from him. I sense that you are making good progress in your electronics , but you are going to come out on the short end of a flame war when you take sides with either player when they both are credible and 30 + years your senior (in experience)

Do you have any products that aren't? :-)

Datasheets have numbers, so I use them. Some jfets have 12:1 Idss specs; some bipolars are binned to below 2:1 beta spread. Sometimes all that matters is a min or a max. Some parts, like tantalum caps, can explode at half their rated voltage. Some parts, like ceramic caps, can lose half their capacitance at rated voltage.

Once in a while I cheat in one direction or the other, but that has to be done very carefully, and only if there's a real payoff. But mindlessly following a rule of thumb that someone taught you 40 years ago is restrictive.

(Actually, I still do one of those: I don't like to leave bases open, even when the resulting leakage is demonstrably trivial.)

That's not the point; few people design electronics (or music, or pastries) that are outside the laws of physics. The point of electronics design is to invent new architectures to solve new problems, and then to make them work.

Physicists are notoriously bad circuit designers. Chemists are worse.

Cool. Please expand on one or two of them.

John

Well, there was the faster-than-light coax running around the NG a couple of years ago. ...and if you pop over to sci.electronics.basics, there's oodles of the stuff from Cahill. ;-)

Please! I'm straight.

John

Is Rich getting jealous? Come on Rich, you at least have to show some booty first ;-)

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

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Tim is obviously on the autistic spectrum; possibly quite a few wavelengths into the spectrum. Look at his website. At his age he should be chasing nubile women. He has his whole life ahead of him to heat up pipes with coils.

The hell. He should be getting drunk and going clubbing every Friday. The hell with electronics, it'll still be here in ten years. Youth? Not so much.

They're almost always hard, because we crank up the specs or the channel count or the feature list until they are.

John

Jim, its a free market.

If John can sell his products and does not get sued for breach of contract ( does it work as advertised), why would you care?

Or do you want the government to regulate ALL products made in the US ?

I didn't think so.

Yes, so?

No, he simply wants to pick apart John's designs.

You're new here, right?

As has been already asked, why does Jim have a hard on for John.

But, I guess you have already expressed that.

Not so new, to not be able to recognize a jerk wanting attention.

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In the same way the space shuttle was spec'd by a roomful of geniuses as just a big bus with wings for flying to the moon. Except it couldn't.

I know what's in some of Larkin's stuff--I've seen schematics. Not trivial, and not obvious. All of it workmanlike, some of it is, honestly, brilliant.

-- Cheers, James Arthur

Professional rivalry. It's the way of SED. It sure beats listening to Slowman whine.

...eye of the beholder.

Yeah, totally trivial.

If your products are limited by boring old physical laws, why bother?

[...]

--

John Devereux

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to

As if krw's output had any redeeming social - or any other - value. His politics are right wing stupid, and he has nothing to say about circuit design.

-- Bill Sloman, Nijmegen