Can someone who is familiar with Tesla's wireless transmission of
power explain how this was to be achieved? I have a lot of info but I
can't get a coherent picture.
During Tesla's radio experiments he apparently discovered the same
thing that physicists re-discovered in the 1950s: the fact that
lightning strikes produce a ringing VLF wave at around 8Hz. This
occurs because the powerful radio pulse from lightning becomes trapped
between the ground and the ionosphere, and it travels repeatedly
around the Earth many times before fading away. The Earth behaves as
a giant transmission line, and since this transmission line wraps back
upon itself, it's also a resonant chamber.
Besides the 8Hz fundamental frequency, numerous higher harmonics would
also be present, since two, three, four, etc. waves could fit in the
circumference of the Earth. The resonance effect as a frequency band
to many kilohertz before the losses become large, where the shortest
waves damp out instead of passing all the way around the Earth. It's
like a "comb filter" with a resonance spike every 8Hz or so, and where
the frequency of these spikes extends up into the kilohertz range.
NASA researchers Sutton and Spaniol used amplified VLF antennas to
explore some of these resonance lines and they found two things: the
"Q" of these resonances are up in the hundreds, and the frequencies
wander around. Drifting frequencies apparently fooled earlier more
primitive spectrum analyzers into reporting a low value for Q. But
drifting frequencies would make it difficult for a transmitter to take
advantage of the high Q, since the transmitter would need to match its
output frequency to a wandering resonance peak.
Tesla apparently planned to broadcast worldwide signals as well as
usable power by sending out narrow intense DC pulses at one of the
Earth's upper harmonics. As with any high-Q RF system, this would
store energy in the (planet-sized!) resonator, leading to extremely
intense sine-wave EM fields all through the chamber (all across
Earth's surface.) The field would be concentrated particularly
strongly at the transmitter and at the opposite spot on the Earth.
A distant receiver with a sharply-tuned resonant antenna should be
able to tap into this field and put out AC power for home use.
Big question: what kind of received power would be feasible? I've
never seen this analyzed rigorously, and if Tesla determined it
experimentally, he kept the results secret. Tesla certainly intended
to run morse-code receivers, stock tickers, and clock motors.
Remotely-powered cars, ships, and planes were discussed in his later
articles, but the accompanying illustrations depict conductive ion-
beams in use, rather than simple radio antennas.
Big question: how could Tesla's 50KHz coil send out VLF power,
broadcasting hundred-Hz or kilohertz pulses? Answer: it's in his
patents. He used a pair of sphere-electrodes in series with that main
conductor which connects the Tesla coil's output to the large sphere-
antenna. The coil would take some milliseconds to build up a high
frequency output. Periodic repeating sparks between these sphere-
electrodes would send out periodic repeating DC pulses on the antenna,
also partially shorting out the Tesla coil each time, and requiring it
to repeatedly ramp up it's high frequency output between these pulses.
Big question: how can a transmitter hit the narrow, wandering
resonance peak frequencies? There's possibly a very interesting
effect here. Perhaps the Earth-resonant EM waves in the environment
might bias the voltage on the transmitting antenna, which would
trigger the periodic sparks early, acting to phase-lock the repeated
sparking to the Earth resonator. In this case the Tesla-coil-
sparkgap-antenna system becomes like a neon bulb relaxtion oscillator,
but with a (planet sized) resonant circuit attached. This would allow
Tesla to adjust his system to lock on to a particular Earth-overtone.
More importantly, it would force the transmitter to alter its
frequency as the Earth-resonances wandered around, so the transmitter
would always broadcast exactly in the center of one of the resonant
frequency spikes.
Tesla's patents also depict resonant "shorting bars" of various
frequencies connected between the antenna and the ground. This
suggests that he intended to emit energy at more than one Earth-
overtone frequency simultaneously. (And he writes elsewhere of
sending out a "wave-complex" with this device.)
Magnifying Transmitter (TMT):
The Magnifying transmitter is just a Tesla coil. If you split the
secondary of a conventional Tesla Coil into two parts connected by a
wire, you can place one part against the primary coil. This lets you
easily adjust the inductive coupling to any desired value. Then also
move the other half of the secondary far away from the rest of the
equipment in order to eliminate unwanted HV breakdown. This is
Tesla's "3-coil" system.
Would this apparatus transmit power
through the air or through the ground? or both?
The energy, the EM waves, would be in the air, while the electric
current would be in the ground. It's much like a ground-plane antenna
system used by AM radio towers and by home CB transmitters. As for
current vs. energy... conventional power lines are analogous: the EM
energy is in the magnetic and electrostatic fields located in the
space between the conductors, while the electric current remains
within the metal. Don't confuse the energy flow with the charge
flow. Remember: EM energy flows from source to load, while charges
sit within the conductor and wiggle back and forth.
What is its purpose?
Is it the main power source in the scheme?
It's like a radio transmitter, but since it "broadcasts" into a sealed
resonant chamber the size of a planet, it's not really radio. It
doesn't lose wave energy off into infinite space. Also, the inside of
a transmission line doesn't obey the inverse-square law, instead it
obeys near-field equations.
Earth / Ionosphere (EI) : Would the TMT charge or discharge the EI?
Nope.
His device should ignore the DC charge already present. However, by
sparking a Tesla coil to an antenna, he repeatedly puts out enormous
DC pulses, causing the Earth cavity to ring with AC sine waves.
Resonance: A lot of what I read proposes putting the EI into resonance
and harnessing the power from this.
No, instead he was hooking his transmitter to a conventional electric
generator, then broadcasting energy without wires. He was harnessing
the resonance EFFECT, harnessing the impedance match provided by hiqh-
Q resonators, not harnessing some unusual energy source. The
broadcast energy comes from coal-fired generators, or Niagra Falls.
How would this be done? I have
some basic knowledge of RLC circuits but don't see the connection
between resonance in a RLC circuit and the ability to buildup
tremendous voltages / currents.
Um... resonant step up? On a swing set, if you lean back in the
swing periodically, you can build up an enormous amplitude. In a
high-Q parallel RLC resonator, if you excite it with an AC low current
at the resonant frequency, you create an enormous current in the coil/
capacitor loop. And in a series resonator, if you excite it with a
small voltage, you create an enormous voltage at the node connecting
the coil and capacitor.
Receiver: Somehow this transmitted power has to be converted to a
useable form. Another RLC circuit to do this?
The "effective aperture" of a small antenna can be enlarged by
connecting it to a high-Q resonator. Of course it helps to have a
large receiving antenna in the first place.
Also see:
Skeptical analysis of Tesla's claimed "non-Hertzian waves"
http://205.243.100.155/frames/Non-Herzian_Waves.html
PBS special on Tesla: Colorado Springs
http://www.pbs.org/tesla/ll/ll_colspr.html
My own article "Tesla's Big Mistake"
http://amasci.com/tesla/tmistk.html
((((((((((((((((((((((( ( ( (o) ) ) )))))))))))))))))))))))
William J. Beaty Research Engineer
beaty a chem washington edu UW Chem Dept, Bagley Hall RM74
billb a eskimo com Box 351700, Seattle, WA 98195-1700
ph425-222-5066
http://staff.washington.edu/wbeaty/
