Wireless energy transfer
LIFE WITHOUT CORDS
Have you ever thought to yourself, "There are too many cords here," or wished you could put an electronic item somewhere else in a room but couldn't because of how far away the plug for you power cord was? That problem could end in the near future. Some scientists have found an efficient way of transmitting power wirelessly. Though there are a few obstacles to overcome, the idea of wireless power seems like a very distinct possibility in the near future.The man given the most credit for the idea of transferring energy wirelessly is Nikola Tesla. Tesla advanced the science of electricity and energy transfer. He invented such things as the transformer, currently the backbone of modern energy transfer. He made other useful inventions such as circuit breakers and condensers; he also came up with an idea for a wireless telegraph, which paved the way for modern radio (Nikola Tesla Museum).Additionally, Tesla played a big part in creating the modern power system. He had a bitter rivalry with Thomas Edison who supported Direct Current (DC) rather than Alternating Current (AC). Edison used DC for his power plants while Tesla tried to convince him to use AC. AC is more dangerous, but it has the ability, through transformers, to be sent much further with little energy loss. The key problem with using DC is that it does not work well over long distances. It is hard to produce the high voltages needed from a power plant in order to easily transport the electricity over distance. If the electricity is transported at low voltages, the current must be increased to compensate for the low voltage. This is not very efficient as seen in Ohm's law.
V= I*R
This equation shows the voltage drop over a given resistance. With the current higher, the voltage lost due to a certain resistance is increased. Since everything has resistance, even with the best wiring, the longer the electricity travels the more of it will be lost. A solution to this is the transformer. A transformer sets up two coils of wires. The first is small and is attached to the power plant. When a current is passed through it, a magnetic field is formed. The second coil is in close proximity to the first and is affected by the field. The second coil has many more wrappings of wire around it. The amount of times a wire is wrapped around a coil determines the effect the magnetic field will have on it. The next equation demonstrates that the voltage changes in relationship to the number of times the coil is wrapped changes. In the equation, "s" stands for secondary and "p" for primary.
