Introduction
Nikola Tesla’s legacy is visible, and utilized by modern life every single day, and his experiments with alternating current (AC) electricity is essential for the power grid. As of now, the AC current that is generated at power plants is transmitted through an incredibly complex network of copper wires and substations, right into our home power outlets. So, a physical connection is required from an electric generator to all units that it intends to power. Nikola Tesla saw this future challenge in transmitting his prized AC current. Through considerable experimentation, Tesla developed a shortcut in transmitting his AC current by sending power through thin air. The contraption which achieved this was the Tesla coil, and its functions are still utilized in modern wireless power and information transmission.
Tesla’s Coil
Tesla’s invention was able to force electricity through the air from one coil to another, but how was this done? The Tesla coil itself was a large copper conductor coil, and a capacitor, which was able to store electric current like a battery. As a generator pumped more and more electricity into the capacitor, it eventually overflows and charges the copper coil, which when charged, creates a magnetic field in the air around it. As more electric charge is deposited, the magnetic field grows larger and stronger, until it is within range of the receiving coil, which in turn, conducts the electric charge through the magnetic field until it has a field of its own. This is how the coil uses electromagnetic induction. These two fields interacting allow greater and greater amounts of electric current to flow back and forth through the empty space between the two coils. If the charge continues to increase from the generator, then the flow of energy can build to a capacity that causes a visible bolt of lightning between the two coils.
The Fault
So if this technology existed in the time of Tesla, then why do we still have a network of copper wire strung along our national energy grid? The problem with this method of power transmission is that it is inefficient for carrying electrical current long distances. The energy can only be transferred between coils when the space between them, or the spark gap, can be penetrated. The spark gap and magnetic field produced is very small in size compared to the distance between a power plant and a domestic home. Furthermore, even the standard magnetic field required a massive amount of voltage to be able to transfer electricity. This fact, compounded with the loss of electric energy in the transmission makes power transfer very inefficient for a large scale power supply. Just because of this shortcoming does not mean Tesla’s invention was revolutionary. The technology that Tesla introduced has essential modern applications.
Tesla’s Legacy
Inventions such as radio and television signals, wifi, and microwaves are all uses of wireless energy transfer. These variations of energy transfer are very useful today because they can be broadcast over very large distances, and require a reasonable amount of power to do so. Today, especially in the information revolution, society could not function without any form of wireless energy transfer. The only way we could stay connected would be through written letters, landlines, and newspapers. So we may not use wireless transfer of electricity on this scale, but it was nonetheless a pivotal step in information and communication technologies.
As far as induction used to transmit a power supply, there are still smaller scale applications today. It it a useful function for charging smaller appliances or batteries, such as phone charging pads, and electric toothbrush charging docks. In addition to this, research is still being performed today to expand the uses of wireless electric transmission by extending the range of electromagnetic induction, and the voltage that can be transferred. Whether Tesla’s coil is used to charge a phone, or broadcast information across the country, it is undoubtedly one of the most important resources available to modern technology.
Works Cited
Paper: “Wireless Non-Radiative Energy Transfer,” to be presented at the 2006 AIP Industrial Physics Forum, Tuesday, November 14, 2006, San Francisco, CA, Moscone. Found at http://www.mit.edu/~soljacic/AIP_press.pdf
Dickerson, Kelly. “Wireless Electricity? How the Tesla Coil Works.”<i>LiveScience</i>. TechMedia Network, 10 July 2014. Web. 19 Feb. 2016.
“Who Invented Radio?” <i>Tesla: Life and Legacy</i>. PBS, n.d. Web. 19 Feb. 2016.