13-02-2016, 11:59 AM
ABSTRACT
A moment without electricity makes your thinking go dry. The major source of conventional form of electricity is through wires. The continuous research and development has brought forward a major breakthrough, which provides electricity without the medium of wires. This wonder baby is called WiTricity.If we are particularly organized and good with tie wrap then also a few dusty power cord tangles around our home. We have even had to follow one particular cord through the seemingly impossible snarl to the outlet hoping that the plug pull will be the right one. This is one of the downfalls of electricity. While it can make people's lives easier, it can add a lot of clutter in the process. For these reasons,scientists have tried to develop methods of wireless power transmission that could cut the clutter or lead to clean sources of electricity. Wireless power transmission is not a new idea. Many researchers developed several methods for wireless power transmission. But WiTricity is a new technology used for wireless power transmission. By the use of this technology transmission of electrical energy to remote objects without wires can be possible. The inventors of WiTricity are the researchers from Massachusetts Institute of Technology (MIT). They developed a new technology for wireless electricity transmission and this is based upon the coupled resonant objects. In this resonant magnetic fields are used. So the wastage of power is reduced. The system consists of WiTricity transmitters and receivers. The transmitters and receivers contain magnetic loop antennas made of copper coils and they are tuned to the same frequency.
INTRODUCTION
Electricity is today a necessity of modern life. It is difficult to imagine passing a day without electricity. The conventional use of electricity is made possible through the use of wires. However researchers in MIT have devised a means of providing electricity without any wires WiTricity, a portmanteau for wireless electricity, is a term coined initially by Dave Gerding in 2005 and used by an MIT research team led by Prof. Marin in 2007.Wireless power transmission is not a new idea; Nikola Tesla demonstrated a "transmission of electrical energy without wires" that depends upon electrical conductivity as early as 1891 The receiver works on the same principle as radio receivers where the device has to be in the range of the transmitter. It is with the help of resonant magnetic fields that witrecity produces electricity, while reducing the wastage of power. This is unlike the principle adopted by Nikola Tesla in the later part of the 19th century; where conduction based systems were used. The present project on WiTricity aims at power transmissions in the range of 100 watts. May be the products using WiTricity in future might be called Witric or Witric's So far the Recently, MIT proposed a new scheme based on strongly coupled magnetic resonances, thus presenting a potential breakthrough for a mid-range wireless energy transfer. The fundamental principle is that resonant objects exchange energy efficiently, while non-resonant objects do not. Figure 1 shows the basic coil system composed of four coils: drive, transmit resonance, receive resonance, and load coils. The transmit resonance coil is coupled to the drive coil which is linked to a power amplifier that supplies energy to the system. The receive resonance coil is coupled with the load coil to provide the power to an external load. The scheme is carried with a power transfer of 60 W and has RF-to-RF coupling efficiency of 40% for a distance of 2 m, which is more than three times the coil diameter. We expect that coupled magnetic resonances will make possible the commercialization of a mid- range wireless power transfer.Magnetic resonancecoupling is a new concept in wireless energy transmission