April 1972 Popular Electronics
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
It is well known that American automobile
manufacturers really dropped the quality ball in the mid-1970s through about 1990. Foreign
car makers were gaining increased access to domestic markets with designs that had more efficient
engines and transmissions with superior materials and techniques, and corrosion control was
much better than most American cars that often began to exhibit rust bubbles underneath the
paint within a year or two - particularly in regions where roadways were salted for controlling
ice and snow. People (like me) who bought used cars were leery about a vehicle with more than
70k-80k miles on them because it was almost guaranteed that a major engine or transmission
repair would not be far off. Foreign cars, buy contrast, were still going strong at 100k miles.
If you were there, you know of what I speak. I mention that background to help explain the
opening statement in this 1972 article describing what could be expected in the near future
with electronics in cars and trucks. A look at the one drawing reveals that by now everything
predicted is now standard equipment even on low-end cars, and of course not many people would
have predicted GPS navigation, Bluetooth-connected tire air pressure sensors, satellite radio,
or even air bags.
More Solid-State Electronics for the New Cars
What Ford and Chrysler are Offering in their 1972 Lines
By John D. Drummond
Chances are that the first car you drive with an on-board
minicomputer that starts the engine, optimizes ignition and air/fuel mix, sets safety mechanisms,
and gets ready to shift transmission, will come from Japan or Germany. The reason such a car
is not likely to come from Detroit is that foreign car firms and electronics companies are
cooperating with each other to develop and deliver sophisticated system packages. The picture
on the domestic front is quite different; a lack of good communications has put the auto men
and electronics men at odds with each other.
There is certainly no lack of expertise or ambition in the U.S. The missing ingredients
are cooperation and understanding. But with no clear, enthusiastic agreement, solid-state
electronics in American-made automobiles has only inched along.
It is obvious that any little "blackbox" electronic package integrated into an automobile
must be able to outfox and outlast the hostile environments created by rough roads, snow,
ice, mud, extreme heat, and extreme cold. Otherwise, the highly practical automobile engineer
wants no part of it, according to Charles T. Mulcahy, a Ford Motor Co. Engineer. He goes on
to say, "If the engine won't start, the car won't go; if the engine starts and the car is
inoperative, the car won't move."
But consider this: the little black box has guided man to the moon and back in spectacular
form. Solid-state devices contain no inherent wearout mechanisms. In fact, thanks to their
proven reliability, solid-state devices and systems are perhaps the only practical and economical
way to realize safety, environmental cleanliness, and the convenience required for tomorrow's
The Pressure is On. With enforcers breathing
down their necks, the auto makers are necessarily devoting most of their efforts to solving
the problem of reducing exhaust emissions and developing passive-restraint devices to comply
with Federal regulations. So, Detroit has had to lay aside, at least for the present, development
and implementation of such exotic things as a single-wire multiplexed system that replaces
the maze-like electrical network wiring harness; radar-based anti-collision and braking systems;
central processor to control antiskid braking; electronic fuel injection; and speed and transmission
The auto men are furious over this stringent Federal legislation. Ernest S. Starkman, a
General Motors vice president, explains that considerable progress has already been made toward
reducing air pollution from automobiles. But pressure for further reductions is a consequence
of impatience with the progress being made in the state of the air in our urban environments.
This diagram shows various items being offered by Ford, though not all of them are available
on all Ford cars. The systems shown are all-electronic.
Whatever the impetus, the electronics industry has a golden opportunity to work with Detroit
in meeting Federal pollution standards. The electronics men feel that solving both the pollution
and passive-restraint problems are within their bailiwick. Presently, however, the auto men
are more preoccupied with grappling with the pollution problem. But some electronic devices
are showing up in Detroit's new cars.
Possible Applications for Solid State in Automobiles
Ford's Better Ideas. Typical of what is being marketed are the electronic
controls in Ford's 1972 line. Not all of the items (see illustration below) are available
in any one model. But they are available in various combinations on all Ford-built cars.
Among the offerings are safety braking for skid control to prevent the wheels from locking
up and skidding should the driver attempt a panic stop on wet, slippery or icy roads. The
system utilizes an electronic computer that goes to work only during an emergency situation
that could cause the wheels to lock. The computer receives speed information from a wheel
sensor through a digital-to-analog (D-A) converter that translates it to a dc voltage before
it is fed to a differentiator and data analyzer. The differentiator output is compared with
a reference signal representing the coefficient of friction of the road surface from the data
analyzer. The comparator output is fed to a logic circuit which determines the amount of braking
required and simultaneously activates a power stage which controls braking.
Automatic speed control is another offering. Using an electronic memory, this system automatically
maintains a constant speed in response to the driver's command. When the car reaches cruising
speed, the driver presses a button. The desired speed is then "memorized" and maintained up-
and downhill and on the straightaway without the driver having to touch the accelerator. When
the brakes are applied, the speed control is automatically deactivated.
A number of safety features have been put into the system to meet the industry's standards.
For example, a redundant brake-disable feature is available to protect against a defective
or poorly adjusted brake switch. Hence, if no disabling signal is received when the brake
pedal is depressed, the speed control will automatically disable when the car's speed drops
to about 8 miles below the speed that was set into the computer.
A distributor modulator is a third offering. Designed primarily as an exhaust control device,
the modulator precisely controls spark advance at speeds in the 25-32-mph range, assuring
more complete fuel combustion.
Diagram of Ford's new anti-skid braking system installation. Computer is
located behind glove compartment. (Photo courtesy of Ford Motor Company.)
There is also an rpm limiter available. It is used primarily in Ford cars equipped with
high-performance engines and manual transmissions. This over-speed limiter keeps the engine
from exceeding a safe maximum rpm limit.
Chrysler's Coming Through. Keeping up with their Detroit rivals, the Chrysler
people are pushing electronics in their ignition systems, a safety braking system, and automatic
The electronic ignition, which eliminates breaker points, looks pretty much like a conventional
system except for a control unit between the distributor and the ignition coil and the addition
of a dual ballast resistor. The electronic circuitry is activated by a pickup coil and is
used to control a switching transistor that opens and closes the primary circuit of the ignition
The great advantage of the breakerless system is lower tune-up cost. A by-product of the
electronic circuitry, claims Chrysler, is that ignition timing and dwell angle are more accurately
controlled than would be possible with conventional breaker points. The end result is better
exhaust emission control.
Like the systems employed by GM and Ford, Chrysler's safety brake relies on a logic computer
to activate a pressure modulator to decrease the amount of hydraulic pressure being applied
to the brake at the wheel which is about to lock up or skid. Where it differs from the competition
is that the Chrysler system prevents front or rear wheel lockup for shorter straight-line
stopping distances. It is claimed that the four-wheel safety braking system makes any driver
better than an expert driving a standard-equipped car in straight-ahead braking applications.
However, as Chrysler engineers are quick to point out, it cannot correct for skids initiated
by bad driving, such as when entering a curve too fast.
The 1972 Chrysler and Imperial model autos are equipped with a second-generation automatic-temperature
control which uses an all-electronic solid-state amplifier to totally control the system's
performance. In prior systems, Chrysler employed a combination of vacu-electronic components
to automatically adjust temperature. This marks the first time that Chrysler Corp. has used
a totally solid-state system employing IC's, transistors, and diodes to control a major system.
The Coming Tide. It is obvious from the foregoing that, in spite of foot-dragging
and lack of cooperation, some inroads are being made by the electronics industry in Car City.
What is also obvious is that, if and when a team effort is finally made, great things are
in store for the average American-made automobile. Let us hope that the animosity gap existing
between the car makers and the electronics industry narrows soon and creates the friendly
conditions needed to bring about cooperation.
Posted July 10, 2017