Engineer and physicist Nikola Tesla (1856-1943) made dozens of inventions and breakthroughs in the production, transmission, and application of electric power. He invented the first alternating current (AC) motor and developed AC generation and transmission technology. Though he was famous and respected, he was never able to translate his copious inventions into long-term financial success. Let's dive deeper and see what we can learn from this great inventor and entrepreneur.
Nikola Tesla was born in 1856 in Smiljan, Croatia, then part of the Austro-Hungarian Empire. His father was a priest in the Serbian Orthodox church and his mother managed the family’s farm. In 1863 Tesla’s brother Daniel was killed in a riding accident. The shock of the loss unsettled the 7-year-old Tesla, who reported seeing visions—the first signs of his lifelong mental illnesses.
Tesla studied math and physics at the Technical University of Graz and philosophy at the University of Prague. In 1882, while on a walk, he came up with the idea for a brushless AC motor, making the first sketches of its rotating electromagnets in the sand of the path. Later that year he moved to Paris and got a job repairing direct current (DC) power plants with the Continental Edison Company. Two years later he immigrated to the United States.
Tesla later wrote that he became interested in demonstrations of electricity by his physics professor. Tesla noted that these demonstrations of this "mysterious phenomena" made him want "to know more of this wonderful force". Tesla was able to perform integral calculus in his head, which prompted his teachers to believe that he was cheating. He finished a four-year term in three years, graduating in 1873.
Tesla claimed that he worked from 3 a.m. to 11 p.m., no Sundays or holidays excepted. He was "mortified when [his] father made light of [those] hard-won honors." After his father's death in 1879, Tesla found a package of letters from his professors to his father, warning that unless he was removed from the school, Tesla would die through overwork. At the end of his second year, Tesla lost his scholarship and became addicted to gambling.
In 1881, Tesla moved to Budapest, Hungary, to work under Tivadar Puskás at a telegraph company, the Budapest Telephone Exchange. Upon arrival, Tesla realized that the company, then under construction, was not functional, so he worked as a draftsman in the Central Telegraph Office instead. Within a few months, the Budapest Telephone Exchange became functional, and Tesla was allocated the chief electrician position. During his employment, Tesla made many improvements to the Central Station equipment and claimed to have perfected a telephone repeater or amplifier, which was never patented nor publicly described.
Tesla arrived in New York in 1884 and was hired as an engineer at Thomas Edison’s Manhattan headquarters. He worked there for a year, impressing Edison with his diligence and ingenuity. At one point Edison told Tesla he would pay $50,000 for an improved design for his DC dynamos. After months of experimentation, Tesla presented a solution and asked for the money. Edison demurred, saying, “Tesla, you don’t understand our American humor.” Tesla quit soon after.
1. The Tesla Coil
A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high-frequency alternating-current electricity. Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits.
Tesla used these circuits to conduct innovative experiments in electrical lighting, phosphorescence, X-ray generation, high frequency alternating current phenomena, electrotherapy, and the transmission of electrical energy without wires. Tesla coil circuits were used commercially in sparkgap radio transmitters for wireless telegraphy until the 1920s and in medical equipment such as electrotherapy and violet ray devices. Today, their main usage is for entertainment and educational displays, although small coils are still used as leak detectors for high vacuum systems.
2. The Magnifying Transmitter
The magnifying transmitter was an adaptation of the Tesla coil. Instead of being designed to discharge to the earth the magnifying transmitter tuned to the natural resonant circuit of the Earth to create standing waves of electrical energy, which could be harnessed by a tuned receiving circuit.
3. The Tesla Turbine
The guiding idea for developing Tesla turbine is the fact that in order to attain the highest efficiency, the changes in the velocity and direction of movement of fluid should be as gradual as possible. Therefore, the propelling fluid of Tesla turbine moves in natural paths or streamlines of least resistance.
A Tesla turbine consists of a set of smooth disks, with nozzles applying a moving fluid to the edge of the disk. The fluid drags on the disk by means of viscosity and the adhesion of the surface layer of the fluid. As the fluid slows and adds energy to the disks, it spirals into the center exhaust. Since the rotor has no projections, it is very sturdy.
Tesla wrote: "This turbine is an efficient self-starting prime mover which may be operated as steam or mixed fluid turbine at will, without changes in construction and is on this account very convenient. Minor departures from the turbine, as may be dictated by the circumstances in each case, will obviously suggest themselves but if it is carried out on these general lines it will be found highly profitable to the owners of the steam plant while permitting the use of their old installation. However, the best economic results in the development of power from steam by the Tesla turbine will be obtained in plants especially adapted for the purpose.
4. The Shadowgraph
Tesla reported that driven by his observation of mysterious damage to photographic plates in his laboratory, he began his investigation of x-rays (at that time still unknown and unnamed) in 1894. Apart from experiments using the Crookes tube, he invented his own vacuum tube, which was the special unipolar x-ray bulb. It consisted of a single electrode that emitted electrons. There was no target electrode; therefore, electrons were accelerated by peaks of the electrical field produced by the high-voltage Tesla coil. Even then, Tesla realized that the source of x-rays was the site of the first impact of the “cathodic stream” within the bulb, which was either the anode in a bipolar tube or the glass wall in the unipolar tube he invented. Nowadays, this form of radiation is known as Bremsstrahlung or braking radiation. In the same article, he stated that the cathodic stream was composed of very small particles (ie, electrons). His idea that the produced rays were minute particles wasn’t wrong at all; many years later, physicists described particle properties of electromagnetic radiation quanta called photons. To avoid heating and melting of the glass wall of his x-ray bulb, Tesla designed a cooling system based on a cold blast of air along the tube, as well as on today’s widely accepted oil bath surrounding the tube.
It also seems that he produced the first x-ray image in the United States when he attempted to obtain an image of Mark Twain with the vacuum tube. Surprisingly, instead of showing Twain, the resulting image showed the screw for adjusting the camera lens. Later, Tesla managed to obtain images of the human body, which he called shadowgraphs. Tesla sent his images to Wilhelm Conrad Roentgen shortly after Roentgen published his discovery on November 8, 1895. Although Tesla gave Roentgen full credit for the finding, Roentgen congratulated Tesla on his sophisticated images, wondering how he had achieved such impressive results. Moreover, Tesla described some clinical benefits of x-rays—for example, determination of foreign body position and detection of lung diseases —noting that denser bodies were more opaque to the rays.
5. The Radio
In 1898 Nikola Tesla developed a radio/coherer-based remote-controlled boat, with a form of secure communication between transmitter and receiver, which he demonstrated in 1898. Tesla called his invention a "teleautomaton" and he hoped to sell it as a guided naval torpedo.
Tesla was very good at getting press coverage for his work, but Marconi came along and captured all the glory and credit before Tesla realized what was going on. Tesla actually invented the idea of the radio in 1892 — not too long after Heinrich Hertz demonstrated UHF spark wireless transmissions in Germany in 1885.
6. The Neon Lamp
Tesla did not invent fluorescent or neon lights, but he did contribute to improving both inventions. He took the lights and created the first neon sign. At the 1893 Chicago World's Fair, he demonstrated neon light signs and how they can make unique designs and even form words.
7. The Niagara Falls Transformer House
When it came to deciding what company would build a power generator at Niagara Falls, Thomas Edison was the first choice. After reviewing Tesla’s work for Westinghouse Electric, though, the Niagara Falls commission went with Tesla’s alternating current power.
Despite doubts, Tesla’s system worked well and became a standard for hydroelectric power.
8. The Induction Motor
Nikola Tesla conceived the basic principles of the polyphase induction motor in 1883 and had a half horsepower (400 watts) model by 1888. Tesla sold the manufacturing rights to George Westinghouse for $65,000.
Most large ( > 1 hp or 1 kW) industrial motors are polyphase induction motors. By polyphase, we mean that the stator contains multiple distinct windings per motor pole, driven by corresponding time-shifted sine waves.
In practice, this is two or three phases. Large industrial motors are 3-phase. While we include numerous illustrations of two-phase motors for simplicity, we must emphasize that nearly all polyphase motors are three-phase.
9. The Radio Controlled Boat
Tesla once said, "The world moves slowly, and new truths are difficult to see." It was his way of responding to the crowd's stunned disbelief upon viewing his scientific wizardry at New York's Madison Square Garden in 1898. Using a small, radio-transmitting control box, he was able to maneuver a tiny ship about a pool of water and even flash its running lights on and off, all without any visible connection between the boat and controller. Indeed few people at the time were aware that radio waves even existed and Tesla, an inventor often known to electrify the crowd with his creations, was pushing the boundaries yet again, with his remote-controlled vessel.
10. Alternating Current
Nikola Tesla was an engineer and scientist known for designing the alternating-current (AC) electric system, which is the predominant electrical system used across the world today. He also created the "Tesla coil," which is still used in radio technology.
They transformed the electrical industry to be able to power motors, transmission systems, and other machines. Not only could it provide power in more ways than one, but it could improve upon the lighting systems, too. In 1886, the entire city of Rome was lit up by the alternating current.
11. Earthquake Machine
In 1893, Tesla patented a steam-powered mechanical oscillator that would vibrate up and down at high speeds to generate electricity. Years after patenting his invention he told reporters that one day while attempting to tune his mechanical oscillator to the vibration of the building housing his New York City laboratory, he caused the ground to shake. During the test, Tesla continuously turned up the power and heard cracking sounds. “Suddenly,” he recalled, “all the heavy machinery in the place was flying around. I grabbed a hammer and broke the machine. The building would have been down about our ears in another few minutes.” Police and ambulances arrived on the scene to attend to the commotion, but Tesla told his assistants to remain quiet and tell the police that it must have been an earthquake.
Tesla never could build this machine.
12. Wireless Energy
In 1901, Tesla secured $150,000 from financier J.P. Morgan to build a 185-foot-tall, mushroom-shaped tower on the north shore of Long Island capable of transmitting messages, telephony, and images to ships at sea and across the Atlantic Ocean by using the Earth to conduct signals. As work began on the structure, called Wardenclyffe Tower, Tesla wanted to adapt it to allow for wireless power delivery, believing from his experiments on radio and microwaves that he could light up New York City by transmitting millions of volts of electricity through the air. Morgan, however, refused to give Tesla any additional funding for his grandiose scheme. (Some speculate that Morgan cut off funds once he realized that Tesla’s plan would have crippled his other energy-sector holdings.) Tesla abandoned the project in 1906 before it could ever become operational, and Wardenclyffe Tower was dismantled in 1917.