where Science went

When Professor Poeschl displayed this uptodate equipment, Tesla intuitively deduced that the commutator was UNNECESSARY and that alternating current (AC) could be harnessd unencumbered. He voiced this opinion, which appeared utterly fantastic at the time. Poeschl devotedd the rest of the lecture to a detailed explanation of how this goal was impossible. Driving the point home, Poeschl embarrased his student by disconnecting the "superflurous" commuatator and noting with feigned surprise that the generator no longer worked. "Mr. Tesla may do many things, but this he can not accomplish. His plan is simply a perpetual motion scheme." Tesla would spend thenext four years obsessed with proving the professor wrong.

 

The AC creation came to be known as the rotating magnetic field. Simply stated, Tesla utilized two circuits instead of the customary single circuit to transmit electrical energy and thus generated dual currents ninety degrees out of phase with each other. The net effect was that a receiving magnet (or motor armature), by means of induction, would rotate in space and therby continually attract a steady stream of electrons wheather or not the charge was positive or negative. He also worked out the mechanism to explain the effect.

Tesla referred to this diagram (or one quite similar to it) in his lecture before the AMerican Society of Electrical Engineers for the first time in 1888. Each square represents the same armature at different points in it's rotation. There are two independent circuits or currents set up diagonally across from one another which are 90 degrees out of phase with each other in both position and timing. So, for instance, in the first position, the armature points to the north pole (of the north/south circuit, which runs from bottom right to top left). The other circuit (running from bottom left to top right) is in the position of changing so that neither pole has a charge. If we look to the next square to the right(which is occurring a fraction of a second later as the currents continue to alternate), we note that the charge is beginning to enter the second circuit (i.e., running from bottom left to top right. ) At this point in the other circuit, the charge is beginning to reverse itself as well but still ahs the same polarity. As there are two north poles set up at this fraction of a second, the armature rotates to go between the two of them. In the third square, the bottom right-top left circuit is now neutralized on its way to reversing it's polarity, while the bottom left-top right circuit maintains the polarity it has just entered. Therefore, the armature continues its movement to the most northward position, and so on.

 

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Sorry can't find the diagram from this book "Wizard" anywhere on the web. It's rather self explainatory though, no?
Buy the book anyway.

Now let us continue on our little journey, hope you're still with me.
Perhaps the death ray would spark interest...
wavelength/4=harmonic of total wavelength (or) required length of coil.
Taking into account the speed of light...and the circumference of the earth, it was determined that coils would have to be "roughly" a mile in length, or some harmonic of this figure, to be in resonant terrestrial frequency. As "the loss of propaged waves is propotional to the cube of the frequency...with waves 300 meters in length, economic transmission of energy is out of the question, the loss being too great. With wave lengths of 12,000 meters loss becomes quite insignificant" (NT, Electrical Review and Western Electrician July 6, 1912. ) Other components included the thickness of the wire itself and horsepower generated. By increasing the frequency between pulsations, the inventor claimed to be able to boost horsepower to a few hundred thousand, although this amount of produced energy would last only a fraction of a second.

 

Czito arrived for work one day in mid autumn to find the inventor vigouruosly watering the ground around the metal plate which he had buried near the lab. "If I could only insulate these wires with liquid oxygen, I could reduce losses another magnitude," the inventor said. "Here, put these on." He gave Czito a pair of rubber soled shoes as he laced up a pair for himself.
"All the way today, sir?" Czito inquired.
"To the limit, my friend. Now remember," the inventer cautined, "keep one hand behind your back at all times...Throw the switch when you see my signal."
...The lanky Serb lumbered from his lab in his high shoes, past the mud, to place testing equipment and cold lamps at various locations in the earth, and positioned himself on a knoll about a mile away, near Prospect Lake. Even though insulated, sparks jumped from the ground to his feet as he crunched along the path.
The sun was low on the horizon as Colorado Springs began to turn on streetlights and electric lamps in prepartion for the night. "Now," Tesla waved as Czito fired up the equipment.
The sound began as a low rumble and built to a "roar that was so strong it could be plainly heard ten miles away." The ground trembled with the noise as the inventor gazed over tto a nearby corral to watch a halfdozen horses rear on their hind legs and gallop frantically away. "Butterflies were carried around in circles as in a whirlpool and could not get out, no matter how hard they tried," (Ibid) as the flume of streamers stormed up the shaft high above the roof of the lab and blustered out from the apex, splitting lightning bolts fully 135 feet in length...Looking to the sky, the wizard held his wireless torches up in triumph as they flickered in the thunder.
The end came abruptly, the Springs plunged into darkness. He had shorted out the town.
Fortunatly "the powerhouse had a second, standby generator which was started up soon after. Tesla was insistent that he be supplied with current from this reserve as soon as it was running, but his demand was refused." Forced by El Paso Electric to fix the damaged generator himself, the inventor was back on line in a day or two. "In the future, he was told, he would be supplied with current from a dynamo operated independently from the one supplying the El Paso Electric company's regular customers.

 

Yes, Shaggie, with one speech Tesla had redinined the motor to which we know it today. This was merley the beginings of his later polyphase system work, in which many of these circuits were placed perfectly random on a wheel (which is harder than it sounds), and the interference incurred from a slight charge there-of only serves as the initial boost necessary to put the machine to work for itself at dramatically incresead ratios.

 

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Yes, so why are we still hooked up to the primitive system of DC power distrubition as well?

 

Grid electricity is AC (in Europe at least though I cant imagine anyone would use DC for transmitting high voltages). Most applicances convert this to DC to run on though.

 

Some HV transmission is still done with DC, particularly underwater. This is done to avoid capacitive and dielectric losses inherent to AC. Voltages are typically in the 500 kV to 1 MV range.

Rather than transformers, conversion to AC at either end of the DC link is done with electronic inverters, utilizing mercury switching tubes or stacks of SCRs, A typical setup is the Pacific Intertie in the western US:

http://en.wikipedia.org/wiki/Pacific_Intertie

While DC is completely ridiculous for local power distribution, it has some advantages at extremely high power levels.

http://en.wikipedia.org/wiki/High_voltage_direct_current

 

Wouldn't it be a whole hell of a lot simpler to completley convert everytthing to AC thus emiminating the need for all that mess?

 

Every technology has its purpose. In some situations, the advantages of HVDC transmission (lower transmission losses, ability to carry more power on existing powerlines) outweigh the disadvantages (cost of inverter stations, power lost in rectification/inversion).

EVERYTHING in engineering involves a series of trade-offs. Insisting on applying one technology to every problem makes no more sense nowadays than it did when Edison insisted that DC should be used everywhere and AC should be banned....

 

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So true so true Ellis.
But you know, there are many applications where AC would be much more efficient like in power generating stations which create energy in DC, then convert it to AC, then convert it back to DC again. It is absurd in my opinion. the Edision/Morgan dynamo detested the idea of using the natural oscillating ehter incarnate as high potential alternating current. This is a fact. But what's insane is so must everyone else henceforth.

 

hah hadn't heard that one. the campaign he saught out to dismantle true science is obtuse. but that line was rather clever, i have to give it to him.

 

Edison would stage traveling shows for the public, in which dogs and other animals (including an elephant) were electrocuted with AC, as a method of showing how "dangerous" it was. He also reportedly pulled political strings to make sure that the new electric chairs being installed in prisons were powered by Westinghouse's AC.

Edison missed the boat on another key technology, as well--the vacuum tube.

He was the first to observe the phenomena (with characteristic humility he termed it the "Edison Effect") that enabled the development of the electron tube, but because of his "DC mindset", he couldn't see any utility in a device that could convert AC to DC--or detect radio signals!

 

are radio waves and ac similar?

 

Which powerplants generate at DC? The only ones I know of are the plants that feed subway systems and such, where DC is needed to run traction motors.

AFAIK, the overwhelming majority of commercial powerplants generate AC directly.

 

Oh well thank Tesla for that one too.

what is AFAIK?

 

AFAIK= As Far As I Know.

Radio waves ARE AC.

Powerline electricity alternates at a frequency (in the US) of 60 Hz, or 60 cycles per second. AM broadcast signals alternate at a frequency between 540,000 and 1,600,000 cycles per second (540 KHz to 1.6 MHz). FM broadcasting runs between 88,000,000 and 108,000,000 CPS, or 88-108 MHz.

Exactly the same thing, just different frequencies.