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opportunist 25
the blatant
by Don Lancaster
Elegant Simplicity
O ne of the goals I have consistently sought out over
and very small size. Perfectly matched to both the user and
the job to be done. Use of the absolute minimum of force
concentration to reliably carry out one well defined task.
While a throwaway item intended for one time use, these
last forever. A classic in every sense of the word.
the years is to develop designs and products which
inherently possess an elegant simplicity . Like many
truly great concepts, elegant simplicity can be hard to pin
down. But you sure know it when you’ve got it.
One clue is when industry insiders end up shaking their
heads in stunned disbelief.
Elegant simplicity combines the best of Schumacher’s
"do more with less" and Buckminster Fuller’s "appropriate
technology". Yeah, Whole Earth Catalog stuff. It goes way
on back to that ancient Ockham’s Razor principle of the
most fundamentally direct explanation often ending up the
most correct. Or Einstein’s "Always seek out the simplest
possible solution – but none simpler" .
Probably the best way we can get a handle on elegant
simplicity is to look at several products and designs that
clearly have it. Here are my selections for a few of the all
time winners…
What is the simplest possible electronic oscillator you
can build? For square waves, the Schmidt Oscillator wins
hands down. It uses 2-1/6 parts, always self starts, is fairly
temperature and voltage stable, and outputs more or less
symmetric square waves. This dude can be micropower at
low frequencies and drives fairly heavy loads.
The key is to pick any CMOS gate or inverter that has
Schmidt Trigger inputs having hysteresis . One-sixth of a
74HC14 is a good four cent starting point. If a rising input
voltage goes past an upper trip point , the output goes low .
If a falling input voltage goes below the lower trip point ,
the output goes high .
On power up, the capacitor cannot instantly charge, so
the input will stay low, and the output will flip high. This
starts charging the cap, slowly raising your input voltage.
When the input voltage reaches your upper trip point, the
output flips low. Now, the resistor starts discharging the
capacitor towards ground. When it hits the lower trip point,
the process repeats.
The choice of resistor and capacitor value determines the
time constant and thus your oscillation frequency. Start off
with a 220K resistor and a 0.001 microfarad capacitor for
something in the mid audio range. Variable resistors or
switched capacitors can be added to extend the range.
All of which gives us a nearly pure implementation of
integrating a square wave to get a triangular wave and then
comparing the limits of the triangular wave to produce an
inverted square wave.
Self-starting is inherent. The very first cycle on power
up will be longer than the others. Which can be handy for
such things as auto-repeat functions on a keyboard.
More details on Schmidt oscillators can be found in my
I consider the P-38 can opener to be by far the finest
invention of the twentieth century. Bar none. Compared to
the P-38 , such utter frivolities as radio, television, autos, or
aviation are not even in the same league. Yes, even Hostess
Twinkies pale by comparison.
For sheer bang for the buck and inherent ergonomics,
nothing can remotely compare. The P-38 opens cans. Any
classic tin can, any time, any place. It runs forever. No
batteries required. Fully portable. Self-protecting. Cost is
zilch. No user manuals or tutorials.
Let’s see what we got here. Two tiny pieces of stamped
steel. One is grooved for extra strength. The blade folds
flat for storage or pops open for use. The first time you see
one, you will swear that it couldn’t possibly work. But it
sure does. The secret is "walking" around the folded rim
present on all classic cans. Your thumb and forefinger form
a double lever that pivots on that rim. With a surprising
amount of force magnification. Probably many tons of
pressure per square inch at the blade edge.
The elegant simplicity here is profound: ultra low cost
January-February, 1994
Midnight Engineering
Copyright c 1997 by Don Lancaster and Synergetics (520) 428-4073 www.tinaja.com All commercial rights and all electronic media rights fully reserved.
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nicely oscillating, how do you keep your output amplitude
constant and undistorted?
The key secret is to add some sort of stabilization to
your amplifier. Raise the gain to start, and then carefully
and continuously adjust the gain to hold your desired low
distortion output. Such circuits are called AGC loops, short
for Automatic Gain Control . As a further complication, you
want your AGC loop to only respond to long term changes
and not to those cyclic variations of each individual cycle.
Otherwise, you just may increase, rather than decrease your
distortion through intermodulation.
The traditional electronic solution here is to use a peak
detector, integrator, and variable gain amplifier stage. A
royal mess still today, but a real bear back in 1940 .
Well, Mister Hewlett or Mister Packard (I forget which
one) decided to use elegant simplicity instead. They noted
that a pilot light is a nonlinear resistance . The resistance is
low when cold and higher when hot. Which is why most
light bulbs will burn out on power on. Further, there is a
thermal inertia to a lamp that only allows its resistance to
slowly change at the required subaudio rates.
By using a plain old pilot light as your AGC loop, you
can eliminate any need for anything fancy.
On power up, the bulb is cold and you get lots of gain.
During run time, the oscillator cycles at its normal safe
low-distortion output value. If the gain goes up, the current
through the bulb and its resistance also goes up, lowering
the gain. In a tight self-stabilizing loop.
The rest, as they say, is history.
This one is nothing but a Tee shaped pipe. Blow air in
the middle arm, and hot air comes out one end and cold air
out the other. To -40 degrees and tons of refrigeration.
With zero moving parts.
Important uses are electronic cabinets, sewing machines,
and general machine shop aps.
Shop air gets blown into the middle arm. This creates an
internal hollow supersonic cyclone that travels at a speed
of several hundred thousand RPM . The cylcone moves to
the hot end, and a fraction of it exits.
Now for the tricky part: The remainder of the cyclone
works its way back towards the cold end, inside the entry
vortex. The velocity is still the same, but the radius is less.
Thus, the angular momentum of the inner vortex has to be
lower than the outside one. But since energy has to get
conserved and since the angular momentum has obviously
dropped, there has to be a net transfer of heat energy from
the inner vortex to the outer one. The result is that the outer
vortex heats, and the inner one cools. Finally, the highly
cooled inner vortex exits via the cold air port.
An optional screw adjustment selects the cold fraction.
Which lets you select your choice of maximum cooling or
minimum temperature.
Two sources of vortex coolers are Vortec and Exair .
Battery testers can be a real hassle. First, you have to
find a load resistor that is properly rated for the exact cell
or cells you are measuring. You then actually measure the
current or voltage under load and compare this against a set
of design curves. Then you interpret the results.
The Duracell folks came up with a better way. They
have literally printed their battery tester onto the blister
package their cells come in. At stunningly low cost.
A marketing solution that is off scale when it comes to
elegant simplicity. Any five year old can use it.
Here’s how this gem works: A conductive pattern is first
printed that forms a resistor. The resistor value is carefully
matched to the cell being tested. The trapezodial shape of
the resistor is carefully selected so that the power density
changes along its length. As a result, the top of the resistor
gets hotter than the bottom. When connected to the test
battery, a temperature gradient is formed, hot at the thin
top and cooler at the thick bottom.
A temperature sensitive liquid layer has been printed on
top of the test resistor. The transition temperature of the
liquid crystal produces a bright green spot. The fresher the
battery, the higher the spot moves up on the display.
Would you believe that the entire Hewlett-Packard
empire was based on one dimly lit pilot light?
The first H-P product was a low distortion, wide range
Wein Bridge audio sinewave oscillator.
A Wein Bridge consists of a single pole RC high pass
filter in series with a single pole RC lowpass filter. The
gain of this network will be zero for very low or very high
frequencies. The gain will be highest at a frequency where
the time constants match. If the resistors are equal, the gain
at the magic frequency will be 0.33 or one-third. Phase
shift will also be zero at this frequency.
To make an oscillator out of this, you simply place an
amplifier with a gain of 3.0 around the loop.
Whoa, not so fast. How do we get started? You have to
provide a much higher gain for startup. And once you are
Midnight Engineering
January-February, 1994
Copyright c 1997 by Don Lancaster and Synergetics (520) 428-4073 www.tinaja.com All commercial rights and all electronic media rights fully reserved.
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Adobe PostScript
1585 Charleston Road
Mountain View, CA 94039
(800) 833-6687
Dallas Semiconductor
4401 Beltwood Pkwy S
Dallas, TX 75244
(214) 450-0400
1250 Century Circle N
Cincinnati, OH 45246
(513) 671-3322
401 N. Washington St.
Rockville, MD 20850
(800) 638-9636
Information Storage Dev
2841 Junction, #204
San Jose, CA 95134
(408) 428-1400
6359 Auburn Blvd, Ste C
Citrus Heights, CA 95621
(916) 721-8217
10125 Carver Road
Cincinnati, OH 45242
(800) 441-7454
Whole Earth
27 Gate Five Road
Sausalito, CA 94965
(415) 332-1716
Back in its vacuum-tube heyday, the nine cent NE-2
neon lamp was by far the most versatile electronic part.
Besides the classic flasher circuit I have shown here, the
lowly neon lamp had an amazing variety of uses.
Stuff like a universal power tester, lightning protection,
surge arresting, lamp dimming, electronic organ tone
generation, bistable and astable flip flops, ultra cheap
voltmeter replacements, twinkle lights, hot-chassis warning
devices, polarity indicators, microammeters, radio tube
filament checkers, long life pilot lights, pulse generation,
electronic switch, threshold detector, ac-dc discriminator,
touch switch, strobe light, synchronizer, radiation detector,
ultraviolet sensor, threshold comparator, voltage regulator,
turntable speed control, reference supply, dc coupler, or a
sawtooth signal source. Plus bunches more.
Basically, you’ve got a small glass tube filled with low
pressure neon gas, supporting two wire electrodes. While
normally an open circuit, the neon ionizes when the supply
voltage exceeded 90 volts. Once ionized, the lamp lights
brightly and conducts heavily. When the supply voltage
under the high current discharge drops below 55 volts, the
lamp will extinguish and the cycle repeat. Only the positive
terminal lights under DC . Both light under AC .
Sadly, the generally lower voltages of the solid state
revolution sidelined the NE-2 into an undeserved early
retirement. Yeah, they still cost less than a dime.
One superb example of elegant simplicity is WPL . An
obscure scripting language for the Apple IIe AppleWriter
word processor written by Paul Lutus. This real gem is a
interpretable language that can automate word processing
tasks. Elegantly and gracefully.
The WPL interpreter was written in a mere 1700 bytes of
lovingly hand-crafted machine language code!
Portions of the general purpose PostScript computer
language clearly offer elegant simplicity. Particularly its
total device independence, its use of procedural character
paths, graceful sparse curves, and powerful dictionary
structures. Plus all the continuous on-the-fly high speed
graphical transformations. Not to mention the power
goodies in level II involving forms, FAX , open font paths,
and outstanding color options.
My own personal favorite elegant simplicity ploy? Way
back when I was in college, I used to consistently get the
highest grades on my lab reports. Mostly because my lab
reports were always thicker than the rest. The key secret to
writing thick lab reports? Thick paper!
I have shown some follow-up names and numbers in the
elegant simplicity resources sidebar. More on PostScript
and such appears on www.tinaja.com .
But what did I miss? Surely you have several favorite
examples of your own. Let’s make a contest out of it. Just
jot down your best shot at elegant simplicity and send it to
me at Synergetics . There will be a dozen or so Incredible
Secret Money Machine II books going to the winners, with
an all all expense paid (FOB Thatcher, AZ) tinaja quest for
two going to the very best of all. Let’s hear from you.
What else?
Let’s see. What else passes our elegant simplicity test?
Vise Grip pliers fer sure. That old plastic nut starter from
Heathkit . Or their integrated circuit extractor that can be
approximated by a bent nail.
I kinda did like those Conanda Effect auto windshield
washers that showed up a way back. Two fixed grooves in
a simple fluidic nozzle that swept the washer glop all over
the glass. Or Volkswagen’s Synchro 4WD van that once
and for all solved positraction problems by its optionally
shoving a locking pin through the differential.
I’m also impressed by those new Analog direct storage
EPROM speech recorders by Information Storage Devices
and Radio Shack . Single chip solutions that eliminate any
need for fancy A/D and D/A conversion. And that Basic
Stamp microcontroller from Parallax .
Or that ultra low cost circuitry used in EKG pulse rate
monitors. A complete micropower short-haul telemetry
system in a cheap throwaway module.
Also by nearly any product that Dallas Semiconductor
makes. Especially their "time in a can" dogtags.
What about the computer languages? Most fail elegant
simplicity and do so abysmally. In fact, one good working
definition of elegant simplicity is What UNIX ain’t .
Microcomputer pioneer and guru Don Lancaster is the
author of 33 books and countless articles. Don maintains a
US technical helpline you’ll find at (520) 428-4073 , besides
offering all his own books, reprints and various services.
Don has a free new catalog crammed full of his latest
insider secrets waiting for you. Your best calling times are
8-5 weekdays, Mountain Standard Time.
US callers only, please.
Don is also the webmaster of www.tinaja.com where a
special area has been set aside for Midnight Engineering
readers. You can also reach Don at Synergetics, Box 809 ,
Thatcher, AZ 85552 . Or email don@tinaja.com
January-February, 1994
Midnight Engineering
Copyright c 1997 by Don Lancaster and Synergetics (520) 428-4073 www.tinaja.com All commercial rights and all electronic media rights fully reserved.
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• Thatcher,
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