|
July 1961 Radio-Electronics
 [Table of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
|
Once again, Hugo
Gernsback's precognitive talent is apparent, these six decades hence since the
publishing of this "Radio Power" editorial in his Radio-Electronics
magazine, this time on the subject of wireless power transfer. Many schemes have been
proposed for transferring power through the ether, using both magnetic and
electric fields, at a wide range of frequencies. Wireless chargers are common
for portable personal devices like cellphones and hearing aids. The power levels
and close proximity of the transmitter and receiver make such applications
reasonable, but always less efficient (i.e., wasted power) than by direct
conductive cable means. One of the most extreme systems proposed for wireless
power transfer is to use space-based solar collectors (which would need to be in
a 33 kmile high, geostationary orbit) and reflectors to beam a concentrated ray
of power to Earth stations for conversion to commercial electric power that can
be added into the national grid. The inefficiency and financial cost of such a
concoction would be immense - not to mention the significant danger to any
airborne entity that might happen to cross the beam's path.
Radio Power
 ... A New Electronic Era is in the Making ...
By Hugo Gernsback
It was in 1899 that Nikola Tesla succeeded in transmitting power without wires.
He probably was the first to light electric lamps at a distance of more than 15
miles from the transmitter, as he did in his historic Colorado experiments. Transmission
at that time was by means of his high-frequency Tesla currents running into millions
of volts. While his wireless power transmission was never practically successful,
due to its excessive cost, it vas nevertheless epoch-making, as were many of his
other outstanding inventions.
We should not be too surprised at the phenomenon of transmitting power through
space without conductors. After all, it has been going on for billions of years.
The Sun, 92,000,000 miles distant, has supplied this planet with inconceivable amounts
of radiant energy for eons.
Because radio waves are in the same electromagnetic spectrum as sunlight, there
is, therefore, no reason why we should not be able to radiate power via radio. What
form this power should take eventually does not seem to matter greatly at present:
Whether the power is primarily radiant heat, as in sunlight, or high-frequency electric
energy to be transformed into electricity or subsequent heat, is of little importance
now. The point is that it is possible to transmit radio power. What is difficult
to believe is that it is not in actual practical use at this moment.
For a partial answer we must look to the transmitter needed, which, until very
recently, was only a theoretical possibility. When we compare the usual radio or
TV transmitter with an electric power plant, the output of the former is puny compared
with the latter. The output of the most powerful radio or TV station is microscopic
at a distance of 1 mile. Only because our receivers can amplify thousands of millions
of times the comparatively weak signals that reach them can we receive such signals.
During the international IRE convention last March, W. C. Brown of Raytheon disclosed
its new amplitron tube, less than 6 inches in diameter, that produces over 1,000
kilowatts of radio-frequency power at microwave frequencies. This is one of the
first tubes designed and built to radiate radio power. It is a history-making beginning.
Certainly much work remains to be done before radio power will become an established
industry. But it will come, we are positive, during the next few decades.
There certainly is no reason why radio power stations of from 100,000 kw to 500,000
kw and more should not be built in the foreseeable future, once all the engineering
problems have been solved. And while it is true that radio power - like all electro-magnetic
radiation - decreases as the square of the distance, radio power at first probably
will not be sent over great distances.
The coming new radio power will have its most important uses wherever it is impossible
or impractical to use conductors or string wires. Automobiles, particularly in cities,
in the future no longer will spew their poisonous fumes - they will be electrically
powered from overhead street-corner radiotors (short for radio-radiators). Radio
power will come into its own somewhat later when new techniques will have been evolved
to make it far more economical than its present contemplated uses. We refer to coherent
quasi-optical beams, wherein very little energy is wasted. Even by using parabolic
reflectors, as we do now with microwaves, far too much energy is lost. By using
"tight" non-spreading beams (as we do with the ruby maser today), we can transmit
radio power over respectable distances.
It may sound fanciful now that future spaceships traveling between the earth
and the moon will be energized from distant radio power transmitters, yet 50 years
hence it probably will be accomplished.
Long before that the space-weather-astronomical stations, 22,000 miles up, which
will orbit "stationary" above the earth, would be supplied with radio power for
heat and energy, necessary to their personnel and maintenance.
When one brings up the subject of radio power and beaming large amounts of energy
into space, the inevitable "death ray" of science fiction necessarily comes to mind.
*
While under certain conditions strong radio power beamed on a subject might prove
lethal, it is known that with specific precautions, radio energy will not be more
dangerous than present-day electric power transmission lines or ordinary house current.
After all, our modern civilization offers no more dangers than prehistoric man faced
in his "civilization". Progress may bring new forms of dangers, but modern man takes
them in his stride. Progress brings untold advantages, too, and radio power will
bring many. - H.G.
* See Lethal Radio Waves, Radio-Electronics, August 1959.
Posted September 12, 2024
|
