Thursday, February 16, 2006

Nikola Tesla's Rise To Fame in the 19th Century

Tesla, Nikola (b 1856, Austro-Hungary, d. 1943, New York)

1856: Birth of Tesla during the night between the 9th and 10th of July in Croatia. His father Milutin (?-1879) was an Orthodox priest. His mother Djouka (?-1892), although illiterate, reportedly invented many small devices for household chores. Perhaps she is the source of Tesla’s future inventing skill. He also had an older brother, Dane (1849-1861).

1861: At the age of five, Tesla built a “toothless” waterwheel. Despite not having the paddles possessed by every waterwheel Tesla had ever seen, this wheel spun evenly in the current. Much later in his life, Tesla would develop a similar design into a bladeless turbine.

Another experiment he attempted was a “sixteen-bug-power motor” made by gluing June bugs to a windmill like apparatus. Unfortunately, before he could test out the engine, his bugs were eaten by one of his young friends, much to the inventor’s disgust.

1861: Death of Dane. In his early life, Nikola was often overshadowed by Dane, first by the family’s belief that Dane was the smarter child, and then by his early death.

“The recollection of his [Dane’s] educational attainment made every effort of mine seem dull in comparison. Anything that I did merely caused my perants to feel theloss more keenly” – Tesla, My Inventions.

1862-1866: Tesla attended elementary school in Gospic, Austro-Hungarian Empire.

1866-1877: Tesla attended Real Gymnasium in Gospic

1870-1873: Tesla attended Gimnazija Karlovac, Rakovac, Croatia

1874: Recovering from sickness, Tesla spent a great deal of time reading. He later recounted this in “My Inventions”

``I had hardly completed my course at the Real Gymnasium when I was prostrated with a dangerous illness or rather, a score of them, and my condition became so desperate that I was given up by physicians. During this period I was permitted to read constantly, obtaining books from the Public Library which had been neglected and entrusted to me for classification of the works and preparation of the catalogues. One day I was handed a few volumes of new literature unlike anything I had ever read before and so captivating as to make me utterly forget my hopeless state. They were the earlier works of Mark Twain and to them might have been due the miraculous recovery which followed. Twenty-five years later, when I met Mr. Clemens and we formed a friendship between us, I told him of the experience and was amazed to see that great man of laughter burst into tears.''

1875-1878: Tesla attended Graz Polytechnic Institute, studying electrical engineering. To impress his parents and to dispel the shadow of his brother, Tesla worked at his studies constantly, usually putting in twenty hour days at his books – from 3:00am to 11:00pm! It was around this time that he started to think about power generation and transmission. Tesla saw that alternating current (AC) had many features that make it far more desirable than direct current (DC).

Why AC is better than DC

DC systems suffered badly from rapid power loss in the wires that carry it, due to their resistance, which dissipates energy as heat. DC power stations had useful ranges of about two kilometers – meaning every neighborhood would have to posses its own noisy, dirty expensive power station!

In order to be efficient, it is necessary to modify the electricity several times once it is generated. Firstly, in order generate it with out the risk of sparks and short circuits in the generator itself (which would waste the power generated) it needs to be generated with low voltages. Then, in order to avoid the serious heating effects, present at high current, it needs to be transmitted at the lowest current practical, finally for the safety of the user, the voltage needed to be low in the home. However, once DC power was generated, it could not be modified in any useful way.

Power distribution systems based on AC did not suffer from these flaws of DC due to the fact that AC could be transformed. In 1831, Faraday invented the electrical transformer, a device consisting essentially of two (noncontacting) coils of wire. An alternating current input to one loop (known as the primary coil) would generate a current in the secondary loop. The oscillating charges in the primary create an oscillating magnetic field that causes the electrons in the secondary to oscillate too – leading to the secondary current.

The ratio of the voltages in the primary and the secondary was equal to the ratio of the number of loops in the coils. This allows AC voltages to be “stepped” up or down at will, allowing you to generate any voltage you like. DC with its constant flow of electrons does not set up an oscillating magnetic field, so it generates no voltage in the secondary. Of course, being able to generate high voltages is limited by conservation of energy – as the power carried by the current is equal to the voltage times the current, the current in the secondary is related to the primary by the inverse ratio.

Far from being a drawback, the drop in current upon transformation upwards of the voltage allowed the heating effects to be circumvented. With AC, you can generate power at low, safe voltages (and high current) with in the plant, then use transformers to step the voltage up by factors of 100 or 1000, reducing the current by similar factors. As the power loss rate is proportional to the square of the current, this can reduce the power loss by a factor of up to one million! Then, using the mirror image of our first transformer, we can bring the voltage back down (and the current back up) to the generator values (less the small losses) – or what ever values are considered appropriate for the market, usually 100-200 V in most parts of the world.

Despite all these advantages, Tesla’s professors were unenthusiastic about implementing an AC system – among many technical challenges that had prevented any success in the past were the violent vibrations the constantly reversing current caused. Tesla, undaunted continued to pursue a solution.

1878: Tesla returned home after his father suffered a stroke. Milutin’s health declined and he died not long afterwards. With his degree little more than half completed, Tesla was left without support and forced to abandon his studies.

1880: Tesla audited classes at the Karl-Ferdinand University in Prague. He reportedly supports himself playing pool, regularly winning despite giving his opponents an almost insurmountable head start.

1881: Tesla, hearing rumors of a planned telephone system in Budapest, traveled to the capital only to discover that the planned system is still only a plan. In order to support himself until the system came to fruition, he took on a series of underpaid jobs. He was an engineer for the Telegraph Office, a draftsman for the Central Post Office, a repairman for the American Telephone Company and an electrical engineer for the Budapest Power Company.

Budapest and Tesla's AC Epiphany

The stresses of his situation, on top of his earlier difficulties lead to a complete mental collapse. Tesla became hypersensitive, sensitive to the slightest noise or light to the point of pain. Only his “powerful desire to live and continue the work” (Tesla) on AC permitted his recovery.

Tesla recovered from his collapse, but he was forever stricken with various obsessive compulsions. He required that any time he had to repeat his actions (like taking a step on a walk) the number of repetitions had to be an exact multiple of three. He also felt compelled to measure his food and calculate its exact volume before he ate any of it.

It was on a walk with his assistant Antal Szigety in Budapest’s Varosliget city park (while reciting from Goethe’s Faust) that he was inspired with the solution to the AC vibration problem.

Old designs for motors consisted of a single current loop. As the AC voltage swapped back and forth, this would generate a magnetic field that would switch direction back and forth each cycle. As the direction changed, a magnet attached to the drive shaft of the engine within the coils would flip over, aligning itself with the field. However, if it was stationary originally, the flipping would happen at irregular times and not always in the same direction. You could overcome this for a while by supplying some energy to start the magnet rotating in the correct sense, with the correct frequency at first, but as this energy was dissipated, the irregularity would resurface.

Tesla’s AC motor design consisted of two coils of wire, positioned at right angles to each other. If the AC current was supplied to the two coils such that the current in one was one quarter of a cycle ahead of the other, the current would create a magnetic field that, instead of flipping, would rotate around. This field exerts a constant torque on a permanent magnet, spinning the driveshaft smoothly. By having the two loops, the engine would rotate smoothly rather than vibrating.

By reversing the system, and driving the permanent magnet with the force generated by, for example, steam, a current would flow in the coils - for AC, the generator and Motor are the reverse of one another.

In his autobiography, Tesla wrote: “A mental state of happiness about as complete as I have ever known in my life. Ideas came in an uninterrupted stream and the only difficulty I had was to hold them fast... In less than two months I evolved virtually all the types of motors and modifications of the systems which now identified with my name.”

1882: Realizing there was no-one in Budapest able to help him develop his new power system, Tesla took a job with the Continental Edison Company in Paris. Quickly recognized as an excellent engineer, he was designated the corporations “fix-it guy”. Tesla rapidly solved many of the company’s most difficult challenges. While working on the lighting system at the Strasbourg Rail Station, he constructed his prototype AC motor and generator. In typical Tesla style, at no point did he use any detailed engineering drawings in the design or construction, yet the model worked first time!

Once his work on the railway station was finished, Tesla was denied the bonus he had earned for the task. He had also failed to raise the interest of Parisian investors in his AC power models, so he packed his bags and spent his entire savings on a ticket for New York

1884: Tesla landed in New York with a grand total of 4 cents and a book of poetry to his name.

Edison "Westinghouses" an Axe Murderer!

An anecdote about Tesla’s interest in poetry is told by the Serbian writer Stijacic. On his first trip to America as a young writer from the Serbian Federation, he was surprised to find in the Chicago Public Library, a book of poems, the author of which was the popular Serbian poet, Zmaj-Jovan. The translator was Nikola Tesla. Later, when Stijacic met the inventor he said, "Mr. Tesla, I did not know that you were interested in poetry."

A look of wry amusement shone in the inventor's eyes. "There are many of us Serbs who sing," he said, "but there is nobody to listen to us."

Tesla immediately went to work for Thomas Edison. Edison, not very interested in Tesla’s AC plans, recognized his troubleshooting skills and put him to work on improving the DC generators that Edison’s DC power distribution network required. Much like his college days, Tesla launched himself into his work, typically in the lab from 10:30 in the morning to 5:30 the following morning!

Soon Edison, who Tesla idolized, presented him with a challenge – if he could improve the efficiency of his DC dynamos by 25%, Edison would pay him a bonus of $50000. Before the two month deadline was past, Tesla had more than succeeded – the dynamos were now 50% more efficient! Sadly, Edison’s tightfisted nature won out and he refused to pay Tesla his promised bonus. In disgust Tesla quit, his hero worship vanishing. In 1931, he told the New York Times: ``If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search.'' ``I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor.''

1885: Tesla formed the Electric Light & Manufacturing Company with a group of investors to capitalize on an arc light design of his. Unfortunately, in his business naiveté Tesla allowed himself to be quickly swindled out of the company by his former partners and over the winter of 1886-1887 he supported himself by digging ditches for only a few dollars a day.

1887: Finding more trustworthy partners in the form of April, Peck and Brown, Tesla founded the Tesla Electric Co. Once more in the laboratory, Tesla returns to the problem of AC motors and generators, and soon files the first of many patents.

1888: He demonstrated his working electric dynamo in a lecture given to the American Institute of Electrical Engineers. Westinghouse heard about this lecture and met with Tesla, buying the rights to all of his patents. Although Tesla made over $100000 over the course of this deal, he made another serious error in allowing Westinghouse to back out of a lucrative clause in the contract that would have guaranteed him $2.50 for every horsepower of generator Westinghouse built.

1890’s: Edison, seeking to discredit AC power, to the benefit of his DC power system, employed an engineer, named Harold Brown to tour the country. In the guise of “Professor Brown”, Brown set up his traveling show at fairs markets and in town commons. His show consisted of the electrocution of animals with both AC and DC. At certain frequencies, even low power AC confuses the electrical impulses in the heart, killing the subject quickly, whereas low power DC simply gives mild burns and stuns. Brown went so far as to conduct the first execution by electrocution – Axe Murderer William Kemmler of New York was “Westinghoused” – with a Westinghouse generator secretly acquired by Edison – in a particularly inhumane manner. The electrocution was not instantaneous, and Kemmler was slowly cooked by the current. In actuality, the 60Hz frequency Tesla implemented in the United States is does not affect the heart as strongly as other frequencies, such as the 50Hz standard inexplicably adopted by Australia.

Tesla's Greatest Triumph and His Descent Begins

At the same time, Tesla and Westinghouse were making their own PR strides that nullified the efforts of Edison. Westinghouse wont he contract to light the Chicago Exposition. President Cleveland himself threw the switch that lit the 100000 lamps in the “City of Light”

During this time, Tesla also worked on frequency conversion, a necessary technology to mesh the Westinghouse transformers (that liked 133Hz) with his own 60Hz Technology. To conduct this, he created the Tesla Coil, which could generate meter long sparks.

Tesla dispelled many of the fears of danger from AC, reportedly by demonstrating how he could run his power through his body, or shoot bolts into the crowd at demonstrations, with no harm (If Tesla did indeed do this, he was rather foolhardy – one can be injured easily by a Tesla Coil, so if you have access to one, you should only use it extreme caution).

1896: Tesla and Westinghouse built the first hydroelectric power station at Niagara Falls, powering the city of Buffalo with AC power, sealing the future of electricity. AC power rapidly became the world standard.

1890’s Tesla began to research high frequency current, leading him to experiments with what were then referred to as “Hertzian Waves” – radio waves. Using the Tesla coil, Tesla generated large fields at high frequencies. Using the Hertzian waves generated by this, Tesla lit light bulbs held in his hands and controlled a radio powered boat with an apparatus he patented. It is not generally believed that Tesla at this point was considering using radio waves to communicate in the style Marconi was only a few years away from demonstrating.

Sadly for Tesla, in 1895, his lab burnt to the ground, setting him back several years. Later that year, Marconi demonstrated in London his radio, using technology that identical to that developed by Tesla. Even though Tesla’s papers had been published in many places and languages, Marconi maintained that he had never seen them and his work was original. For the next few years, both Tesla and Marconi worked on improving their respective systems, but Marconi pulled ahead due to his superior effort at attracting investment.

Tesla instead changed his focus back to his radio controlled boats. He showed a design that could carry six torpedoes with out a crew at Madison Square Garden, but he turned off investors with his “borrowed mind” remote control claims – Tesla told them he was controlling the boat with his mind. It’s not clear what he meant by that statement; was he ironically referring to his mind having come up with the control or was he confused about how his invention actually worked or was did he just accidentally sabotage himself with a little joke?

Tesla had achieved his greatest successes, but now a combination of bad luck, poor planning and mistaken ideas would lead to a fall as spectacular and almost as meteoric as his rise.

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