Electronic Design

Bob's Mailbox

Dear Bob:

I recently read your article on application engineering.  I thought it was a great piece.  I enjoy reading your columns in each issue because they tell it like it really is in the trenches.  You write from your heart and experience, which is rare in technical journalism.  I always learn something from your articles because they cause me to think and feel.

The reason I wrote to you about this application-engineering article is that my first job was an entry position in Central Applications at National Semiconductor in the late 1970s.  I was one of those young kids who came to you for help with questions I couldn't handle.  I remember the first time I saw the awesome filing system on your desk.

Thanks for the help you so willingly offered back then and thanks for the insightful article on the role and importance of AEs today.

I now work for Cadence Design Systems.  Our products are design automation tools for electrical engineers, but your view of the AE role is just as valid in our business as yours.  We have over 300 AEs in Cadence today, with more coming in the future.

They are as vital to our business in providing service and product direction as you mention.  I am going to pass your article on to our AE managers, sales managers, and general managers because I think it offers a great perspective.  It is good advice for AEs and an important wake-up call for those who may sometimes take AEs for granted.

Joseph B. Costello, President and CEO, Cadence Design Systems, Inc., San Jose, Calif.

I'm glad we agree on the value of Apps guys!-RAP

Dear Bob:

Much appreciation for your April editorial that provided a nightmarish peek into the mind of an analog engineer.  I read it with prayer and thanksgiving that I, a digital designer, am spared the futile struggles that must be endured daily in that Slough of Despond called "analog design," where nothing is as it seems, and where there is no bedrock except in pitiless physical laws like Planck's Constant, Heisenberg's Uncertainty, and Rejection Ratios by Power Supplies.

One useful fact did manage to percolate through Mr. Kuzdrall's erudite April foolery.  To wit:

The fundamental minimum energy requirement for an analog computer is directly proportional to the amount of actual information handled by the system.  In a digital computer the fundamental minimum is proportional to the log of the information handled, n'est pas?

Aside from the clear superiority of digital over analog in every field-acquisition, control, computing, simulation, image processing, etc., etc.-there is the outstanding fact straight from the Creator:  The entire Universe in all aspects is digital to its foundations, e.g.

1) Time is digital because all clocks tick.  Even streak cameras have s/n digital limits.

2) Space is digital because there are "forbidden zones" at the atomic level.

3) Matter is digital (as Democritus suspected 23 centuries ago) because it is in fact atomic.

4) Thought is digital because it is a sequence of synapse snappings.

5) Life is digital because the information for every living cell is carried digitally within its DNA.

6) Sound is digital because all organic perceptors have digital design.

7) Acoustic "waves" are digital at the molecular level where they are a sequence of bumpings.

8) Electromagnetic radiation is digital via photons.

9) Color is digital because each and every color in every shade is a digital ratio of R, G, and B.

10) Imagery is digital because all perceptors have pixels, whether organic or inorganic.  The pixels in old-fashioned video are defined by digital numbers like "s/n" and "lp/mm."  The Pointillists were right.

11) Optical images themselves are digital at the diffraction limit.

12) Even snowflakes and tree shapes are digital, since the recent discovery of fractals.

"Analog" in any sense is simply an illusion of ignorance.  The wise analog engineer, living in the late 20th century, will recognize that the time has come to replace his warm heart with a cool head, bit by bit.

Peter R. Vokac, Digital Engineer, Tucson, Ariz.

I shan't bother to rebut your extreme claims that all the world is digital, though readers may wish to do so.  But the next time you need an analog voltage or circuit, and you refuse to use it, I'll feel sorry for you.  What power supplies do you run your computers on, anyhow?-RAP

Dear Bob:

Enjoyed your "dead car stuff" article in the Feb. 6 issue.  You may not be aware of it, but you have pointed out the need for a new product:  a solid-state tail/brake light bulb.

My son owns a commercial trash company, and I assure you a burned out light bulb is no trivial matter today.  After being stopped, the truck is subjected to a safety inspection and paperwork inspection, which often uncovers minor leaks and drips, minor adjustments, and incorrect this or that.

Loss of time/money/income can run into the hundreds of dollars for each problem because of the barbaric 1920s-designed light bulb with archaic socket connections.

The major reason for this problem is severe vibration of the heavy truck.  Even new bulbs last only about a month or so.

Several years ago, I "thought" I saw an LED replacement tail-light bulb.  If you have the contacts, could you please ask if anyone makes them.  I feel a cluster of LEDs grouped together would have enough light to pass as marker lights and tail lights.  The brake light would probably still need the old-style light bulb?  I also feel the truck owners would pay $15 each for replacement tail-light bulbs or marker lights which would not burn out.

Dennis Brigance, Vitro Corp., Silver Spring, Maryland

PS:  If you can't find this thing, ask National to make it.  I'll be your East Coast sales rep.

NSC quit selling LEDs several years ago.  But a smart guy could easily assemble redundant strings of LEDs with ballast resistors and antireversal diodes.  Then the dirty, rusty, bent socket becomes the unreliable element! Good Luck!-RAP

Dear Bob:

This letter is in response to the letter from Neil Iverson of the Boeing Company (February 20, 1982), stating "... nobody makes decent power transformers anymore."

Grand Transformers Inc. is a designer and manufacturer of custombuilt power transformers.  If Mr. Iverson will send us specifications, we will build him a transformer with single or multiple shields, grounded or brought out to an external termination.

And they will be built to comply with any UL, CSA, VDE, or IEC Standard he wishes.  We have built units exhibiting interwinding capacitances as low as 0.05 pF.

The letters in the same issue responding to your article, "What's All This Spicey Stuff, Anyhow (Part III)" (October 10, 1991), was also very interesting to me.

We see the same situation in the transformer field, where so-called "engineers" only know how to "design" transformers on a computer.  I am old enough to say that my first few years were spent using a slide rule.  Today I do use a computer, but only to save computation time.  The designs are still worked out from scratch on paper, and more importantly we still build prototypes to check out the design.  Doverai no proverai!

Keith L. Williams, P.E., Senior Design Engineer, Grand Transformers, Inc., Grand Haven, Mich.

I'm delighted that you still design transformers the right way-by thinking!  Now, if you stocked and sold a "well-shielded F91X" as a semi-standard product, would anybody buy them?-RAP


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