April 1958 Radio-Electronics
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
Ooooh, I should have posted this story about 23 days ago, but better
late than never. I meant to, but forgot. The story documents development
of the "transistom" device back in the 1958 timeframe. Keep in mind
that it was just a decade earlier that Mssrs. Bardeen, Brattain,
and Shockley introduced the transistor amplifier to the world. The
transistom was basically a 3-terminal transistor with two additional
leads for a revolutionary power source built from radioisotopes
of magnesium and manganese. In the day, school kids, including me,
were handed blobs of liquid mercury to inspect and pass around in
class, demonstrating how relatively ignorant we were about things
we now consider to be extreme health hazards. Accordingly, encapsulating
radioactive material in consumer devices was not a concern. The
complete absence of transistoms in the marketplace today speaks
volumes about its success.
This remarkable discovery foreshadows advances in two areas of
the semiconductor field - diodes and transistors - and makes greater
miniaturization possible while increasing transistor sensitivity.
A radio battery with a life of 50 years is possible
Mohammed Ulysses Fips, IRE*
Fips, you engineers are in the stone age," scowled the Big Boss,
savagely biting his 7-inch Havana. "The idea of dry-cell- or house-current-powered
receivers is not only preposterous, it's insane. Prehistoric, that's
what it is! You yak all day long about your glorious science, my
accomplished yaketeer - now come down to earth and compose. I'll
give you 90 days to produce a receiver that needs no dry cells,
no outside current - or else!"
The door banged shut with final explosive emphasis and I knew that
the Chief meant business. Strangely enough, for once I agreed with
the antediluvian coot and found myself even elated with the difficult
assignment. I immediately knew I could produce. Such is the exuberance
of youth! Instanter, within minutes of Bignose's talk, I was deeply
enmeshed in the problem.
A flashlight bulb is connected to the Transistom's atomic
battery to demonstrate its power. The battery can keep the
lamp lit for 50 years.
I soon hit upon the solution. Radio-activity was the answer!
I took out my dusty old handbook on Primary and Secondary Batteries
and soon found that in Volta's and later physicists' potentials-of-the-metal
series, magnesium and manganese have respective voltages of +1.628
for Mg and +1.239 for Mn, or a theoretical. total of 2.867 volts.†
If, I reasoned, I made these two metals radioactive and used
them as an atomic battery, I should get at least 2 1/2 volts per
element. I accordingly secured a small quantity of manganese and
magnesium and took them to the neighboring atomic research plant
on Long Island, whose director I knew. He put the metal bits into
the cyclotron and bombarded them atomically for a week.
Here I should call attention to the fact that my first experiments
had quickly shown that pure metals alone would not work as an atomic
battery. I had to use a magnesium as well as a manganese alloy of
certain proportions, which for patent reasons I cannot divulge now.
I can state, however, that the alloyed metals used were much heavier
in each case than manganese (atomic weight 54.94) and magnesium
(atomic weight 24.32).
After the samples were "cooked" atomically, I called for them.
The tiny pieces had been placed in a thick lead box, although the
director assured me that the quantity of the now radioactive metal
was sufficiently small that all the pieces together were not more
dangerous than a dozen radium-luminous wrist watch dials.
I must also report that before I took the manganese and magnesium
pieces to the cyclotron I had welded the thin 1/8-inch metal squares
together. This was easy because they were almost paper-thin. The
final atomic battery thus consists of a 1/8 x 1/4-inch magnesium-manganese
radioactive strip (Fig. 1). The finished battery gives a voltage
of just over 2 1/2 under a light load. As the load increases, the
voltage of course drops as in an ordinary dry cell. You might wonder
how the atomic battery works with its two main elements welded together.
The answer is no different than in a dry cell in which the zinc
can and the depolarizer (manganese dioxide) are intimately connected
by the electrolyte (sal ammoniac and zinc chloride), which is highly
conductive. Or take a storage battery in which the positive and
negative plates are immersed in a bath of dilute sulfuric acid,
which you'd think would short-circuit the plates.
Naturally, in an atomic battery, the energy is not chemical as
in a dry cell nor "stored" electricity as in a storage battery.
The energy in an atomic battery comes from the gamma radiation,
which is then converted electronically in the two metals. A current
then flows from the manganese to the magnesium.
What is the useful life of an atomic battery? My calculations
show that a conservative estimate is 40 to 50 years. With future
refinements, the life expectancy should be much greater.
My next step, naturally, was to hook up my atomic cell to a transistor,
thus making it possible to construct a small radio in which the
batteries would take up practically no extra room. Curiously, too,
I soon found out that the atomic radiation had a decided influence
on a transistor; it enhanced its sensitivity surprisingly.
The final and successful version is shown diagrammatically in
Fig. 2. Here we have a standard three-lead transistor to which the
atomic battery has been joined. For a number of technical reasons,
the battery elements should not physically contact the transistor
elements, hence I use a thin ceramic separating film. (Other suitable
insulators can be used.) ††
Fig. 1 - The battery consists of two small squares of radioactive
metals - magnesium and manganese - welded together.
Fig. 2 - When the battery is fastened to a transistor, forming
a composite unit, the Transistom is completed.
The transistor battery is now encapsuled, as is standard practice
with all modern transistors. This results in a new electronic device
which I call the Transistom (transistor plus atom). The transistom,
as will be noted, has five leads - three transistor and two battery
leads. These external battery leads can be interconnected as necessary
in various circuits. In a six-transistor set we can even hook all
the batteries up in series, giving us 15 working volts to drive
a large speaker.
Needless to state, the coming transistom circuitry is endless
and the nuisance of battery replacements will soon be a thing of
Long before the 90-day time limit imposed upon me by the Chief,
I walked into his office unannounced one morning. Out of my vest
pocket I pulled a six-transistor receiver. If it hadn't been for
the loudspeaker, the little set would have fitted into an ordinary
matchbox - but the speaker made it 50% bigger.
I put it through its paces and, if I must say so myself, it worked
- as the French would say - formidable. Bignose, for once, was enchanted
as I opened the tiny lid, showing him the "works."
In the office with the all-highest there were also the science
editor and the electronics editor. All three listened politely and
interestedly to my technical description of my transistom. Then
there was a long, thick silence accompanied by pointed headshaking.
Finally Bignose cleared his throat and snickered, "Fips, my boy,
do you ever read the papers and do you know what goes on nowadays?
Did you know that the word radiation is akin to pestilence all over
the world today? What do you think would happen to us if we printed
your transistom story? A radio set that gives off deadly radiation!
Admittedly you - and we - know that it wouldn't hurt a fly, but
what about the public? What about the Radiation Energy Commission
(REC)? What about the National Health Service? People are hysterical
today about any form of gamma radiation. You know that every kind
of X-ray-except in doctors' hands - is taboo now. And now you want
us to publicize a radio set that gives off gamma rays! Indeed!"
"Frank," this to the science editor, "bring in your Geiger counter!"
Frank returned in a minute with the Geiger and brought the probe
to within a foot of my receiver. Of course it clicked furiously,
as was to be expected - it would have done that with a luminous
radium wristwatch dial, too.
"Look here, Fips," rasped Joe, the electronics editor, "can't
you just visualize the ads of the large set manufacturers screaming
'Buy a safe NonRadiation battery set that won't endanger your or
your family's health.' "
"Yes, Fips," piped in Frank, "you must know too that radiation
today is the big political weapon of all our enemies and detractors
the world over. Japan leads all Asia in bellowing at America to
stop all forms of radiation and fallout to safeguard future generations.
European scientists condemn us for the same reason.
"Kruschev, I am positive, would hop on your radiation radio as
an excellent propaganda springboard to denounce our Western decadence
and irresponsibility for foisting more misery and suffering on an
already distressed world, all for the sake of our capitalistic dollar."
"No, Fips," this from the electronics editor, "I know what is
in your mind - you want to encase your chassis in lead to stop all
radiation. That, my boy, is no solution. Aside from the impossible
added weight, think what a picnic the battery set manufacturers
would have in their ads, telling service technicians to stay away
from servicing dangerous radiation sets! Aside from this, shielded
or not, your set would still be taboo - because of its potential
radioactive danger. No, you'll have to start all over. I admit your
scheme is brilliant - but with today's wholly uncalled for radiation
hysteria, you must chart a new course."
Whipped and beaten down once more, I shuffled out the hallway.
At the bend on the wall I glanced at the large leaf calendar and
sadly noted the date:
*Institute Radioactive Engineering.
†A recent magnesium-carbon-manganese dry cell actually
gives 2 1/4. volts.
††My latest transistoms now use light-gauge magnesium
and manganese wires welded together.
Posted April 24, 2014