08-03-2015, 03:27 PM
transfer of power using resonant circuits
|
witricity paper presentation in ieee format
|
transfer of power using resonant circuits
29-03-2017, 04:02 PM
WiTricity is an American engineering company that manufactures devices for wireless energy transfer by resonant energy transfer based on oscillating magnetic fields.
History
The term WiTricity was used for a project that took place at the MIT, led by Marin Soljačić in 2006. The MIT researchers successfully demonstrated the ability to power a 60 watt bulb wirelessly using two 5-coil copper coils Of 60 cm), that were to 2 m (7 feet) of distance, with an efficiency of approximately 45%. The coils were designed to resonate together at 9.9 MHz (wavelength ≈ 30 m) and were oriented along the same axis. One was inductively connected to one power supply, the other to a light bulb. The installation turned on the light bulb, even when the direct line of sight was blocked using a wooden panel. The researchers were able to power a 60-watt bulb with an efficiency of approximately 90% at a distance of 3 feet . The research project became a private company, also called WiTricity.
Emerging technology was demonstrated in July 2009 by CEO Eric Giler at the TED Global Conference held in Oxford. There it refers to the original idea, first applied by the physicist Nikola Tesla between its coils, and shows a WiTricity power unit that feeds a television as well as three different cell phones, the initial problem that inspired Soljacic to get involved with the project .
Toyota maker made an investment in WiTricity in April 2011. In September 2012, the company announced that it would make a $ 1000 demonstration kit available to interested parties, to promote the development of commercial applications.
Technology
WiTricity relies on weakly coupled electromagnetic resonant objects to transfer power wirelessly. This differs from other methods such as simple induction, microwave, or air ionization. The system consists of transmitters and receivers that contain magnetic loop antennas critically tuned to the same frequency.
Because WiTricity devices operate in the near electromagnetic field, the receiving devices must be no more than a quarter wavelength from the transmitter. In the system shown in the 2007 document, this was only a few meters at the chosen frequency. In their first work, the group also simulated GHz dielectric resonators. WiTricity devices are almost wholly coupled with magnetic fields (electric fields are largely confined within capacitors inside devices), arguing that it makes them More reliable than the transfer of resonant energy using electric fields (the most famous in Tesla coils,), since most materials are weakly coupled to magnetic fields.
Unlike distant field-based wireless transmission systems based on traveling electromagnetic waves, WiTricity employs near field resonant inductive coupling through magnetic fields similar to those found in transformers, except that the primary coil and the secondary winding are physically separated and Tuned to resonate to increase its magnetic coupling. These tuned magnetic fields generated by the primary coil may be arranged to interact vigorously with secondary windings adapted in distant but much weaker equipment with any surrounding object or materials such as radio signals or biological tissue.
In particular, WiTricity relies on the use of resonance to achieve high power transmission efficiency. Aristeidis Karalis, referring to the experimental demonstration of the team, says that "the usual non-resonant magnetic induction would be almost 1 million times less efficient in this particular system." Researchers suggest that exposure levels are below the threshold for FCC safety regulations, and radiated power levels comply with FCC radio interference regulations.
Researchers attribute the delay in the development of wireless energy technology to the limitations of well-known physical laws and a simple lack of need. Only recently have modern consumers obtained a large number of portable electronic devices that use batteries and plug-in chargers.
History
The term WiTricity was used for a project that took place at the MIT, led by Marin Soljačić in 2006. The MIT researchers successfully demonstrated the ability to power a 60 watt bulb wirelessly using two 5-coil copper coils Of 60 cm), that were to 2 m (7 feet) of distance, with an efficiency of approximately 45%. The coils were designed to resonate together at 9.9 MHz (wavelength ≈ 30 m) and were oriented along the same axis. One was inductively connected to one power supply, the other to a light bulb. The installation turned on the light bulb, even when the direct line of sight was blocked using a wooden panel. The researchers were able to power a 60-watt bulb with an efficiency of approximately 90% at a distance of 3 feet . The research project became a private company, also called WiTricity.
Emerging technology was demonstrated in July 2009 by CEO Eric Giler at the TED Global Conference held in Oxford. There it refers to the original idea, first applied by the physicist Nikola Tesla between its coils, and shows a WiTricity power unit that feeds a television as well as three different cell phones, the initial problem that inspired Soljacic to get involved with the project .
Toyota maker made an investment in WiTricity in April 2011. In September 2012, the company announced that it would make a $ 1000 demonstration kit available to interested parties, to promote the development of commercial applications.
Technology
WiTricity relies on weakly coupled electromagnetic resonant objects to transfer power wirelessly. This differs from other methods such as simple induction, microwave, or air ionization. The system consists of transmitters and receivers that contain magnetic loop antennas critically tuned to the same frequency.
Because WiTricity devices operate in the near electromagnetic field, the receiving devices must be no more than a quarter wavelength from the transmitter. In the system shown in the 2007 document, this was only a few meters at the chosen frequency. In their first work, the group also simulated GHz dielectric resonators. WiTricity devices are almost wholly coupled with magnetic fields (electric fields are largely confined within capacitors inside devices), arguing that it makes them More reliable than the transfer of resonant energy using electric fields (the most famous in Tesla coils,), since most materials are weakly coupled to magnetic fields.
Unlike distant field-based wireless transmission systems based on traveling electromagnetic waves, WiTricity employs near field resonant inductive coupling through magnetic fields similar to those found in transformers, except that the primary coil and the secondary winding are physically separated and Tuned to resonate to increase its magnetic coupling. These tuned magnetic fields generated by the primary coil may be arranged to interact vigorously with secondary windings adapted in distant but much weaker equipment with any surrounding object or materials such as radio signals or biological tissue.
In particular, WiTricity relies on the use of resonance to achieve high power transmission efficiency. Aristeidis Karalis, referring to the experimental demonstration of the team, says that "the usual non-resonant magnetic induction would be almost 1 million times less efficient in this particular system." Researchers suggest that exposure levels are below the threshold for FCC safety regulations, and radiated power levels comply with FCC radio interference regulations.
Researchers attribute the delay in the development of wireless energy technology to the limitations of well-known physical laws and a simple lack of need. Only recently have modern consumers obtained a large number of portable electronic devices that use batteries and plug-in chargers.
|
« Next Oldest | Next Newest »
|
