The promise of wireless electricity has been around for over 100 years. Nikola Tesla spent much of his productive life experimenting with wireless power, the familiar Tesla coils is actually a resonant wireless power transmitter, and the dream of wireless power was also his undoing when his Wardenclyffe project was terminated in 1904. Over the following decades very little research has been conducted with the prominent exception of Bill Brown who’s experiments in microwave wireless power transmission culminated in a successful demonstration in 1975 by transmitting 30kw over 1 mile at 82.5% efficiency at the Goldstone Deep Space Communication Complex.
Wireless power research was dormant again unit 2007 when an MIT scientist demonstrated wireless powering of a 60W light bulb with 40% efficiency at a 2m (7ft) distance using two 60cm-diameter coils. In 2008 Intel reproduced the MIT group's experiment by wirelessly powering a light bulb with 75% efficiency at a shorter distance.
There are several different wireless electricity technologies on offer:
1. Inductive Coupling
They look like a mouse pad and can send power through the air, over a distance of up to a few inches. A powered coil inside that pad creates a magnetic field, which much like a conventional transformer, induces current to flow through a small secondary coil that's attached to a portable device.
2. Radio-frequency
PowerCast offer a wireless electricity technology based on what's known as radio frequency, or RF. This can transmit power across distances of up to 85 feet. A transmitter plugs into the wall, and a dime-size receiver (the real innovation, costing about $5 to make) can be embedded into any low-voltage device.
3. Laser
PowerBeam showcases wireless lamps and picture frames. Located in Sunnyvale, Calif., the company uses yet another wireless-powering approach. Its technology beams optical energy into photovoltaic cells using laser diodes.
4. Conductive Pad
Boulder, Colorado based WildCharge is demonstrating a mat that uses a conductive powering technique. This is more efficient than inductive powering but requires direct contact between the devices and the charging pad. Though most of the mats or pads on display are intended to power only a handful of devices at a time, WildCharge says the product design is certified for up to 150 watts - enough to power 30 laptops.
5. Magnetically Coupled Resonance
Another wireless power technology is on display in a private suite high in the Venetian hotel tower. Magnetically Coupled Resonance was demonstrated in 2007 when an MIT scientist demonstrated wireless powering of a 60W light bulb with 40% efficiency at a 2m (7ft) and has been dubbed WiTricity. As proof that it works, an LCD TV is powered by a coil hidden behind an oil painting located 5 feet away. Another demonstration involves walking in the direction of another coil with an iPod Touch in your hand, it starts to charge when it gets within two meters.
The technique can power an entire room, assuming the room is filled with enabled devices. Though WiTricity uses two coils, just like the eCoupled system, it differs in that the coils don't have to be close to each other to transfer energy. Instead, they depend on so-called magnetic resonance. WiTricity doesn't depend on line-of-sight. A powered coil in your basement could power the rest of the house, wirelessly.
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Wireless power research was dormant again unit 2007 when an MIT scientist demonstrated wireless powering of a 60W light bulb with 40% efficiency at a 2m (7ft) distance using two 60cm-diameter coils. In 2008 Intel reproduced the MIT group's experiment by wirelessly powering a light bulb with 75% efficiency at a shorter distance.
There are several different wireless electricity technologies on offer:
1. Inductive Coupling
They look like a mouse pad and can send power through the air, over a distance of up to a few inches. A powered coil inside that pad creates a magnetic field, which much like a conventional transformer, induces current to flow through a small secondary coil that's attached to a portable device.
2. Radio-frequency
PowerCast offer a wireless electricity technology based on what's known as radio frequency, or RF. This can transmit power across distances of up to 85 feet. A transmitter plugs into the wall, and a dime-size receiver (the real innovation, costing about $5 to make) can be embedded into any low-voltage device.
3. Laser
PowerBeam showcases wireless lamps and picture frames. Located in Sunnyvale, Calif., the company uses yet another wireless-powering approach. Its technology beams optical energy into photovoltaic cells using laser diodes.
4. Conductive Pad
Boulder, Colorado based WildCharge is demonstrating a mat that uses a conductive powering technique. This is more efficient than inductive powering but requires direct contact between the devices and the charging pad. Though most of the mats or pads on display are intended to power only a handful of devices at a time, WildCharge says the product design is certified for up to 150 watts - enough to power 30 laptops.
5. Magnetically Coupled Resonance
Another wireless power technology is on display in a private suite high in the Venetian hotel tower. Magnetically Coupled Resonance was demonstrated in 2007 when an MIT scientist demonstrated wireless powering of a 60W light bulb with 40% efficiency at a 2m (7ft) and has been dubbed WiTricity. As proof that it works, an LCD TV is powered by a coil hidden behind an oil painting located 5 feet away. Another demonstration involves walking in the direction of another coil with an iPod Touch in your hand, it starts to charge when it gets within two meters.
The technique can power an entire room, assuming the room is filled with enabled devices. Though WiTricity uses two coils, just like the eCoupled system, it differs in that the coils don't have to be close to each other to transfer energy. Instead, they depend on so-called magnetic resonance. WiTricity doesn't depend on line-of-sight. A powered coil in your basement could power the rest of the house, wirelessly.
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This is a recent clipping from the Indian Express, regarding the work of two boys from Bishop Cotton Boys School on WIRELESS ELECTRICITY.
ReplyDeleteThe Indian Express
Bangalore, Thursday, September 27, 2007
BUDDING SCIENTISTS
Electricity in no more a miracle thanks to the efforts of scientists like Nikola Tesla, Thomas Alva Edison, Benjamin Franklin and Samuel Morse. In simple worlds, elecricity is defined as the flow of electrical power or charge through a wire. Omar Ahmed Khan and Daniel Fu, 12th standard students from Bishop Cotton Boys' School have generated a wireless electric circuit which conducts electricity without wires.
The endeavour began in April 2006 which is inspired by the works of Nikola Tesla whose esperiments failed due to lack of funds. Say the young talents, " Though many esperiments have been carried our regarding electricity, there has been a dearth of a full-fledged project. The recent experiment by MIT, where they used a non-radiating magnetic field was also very expensive and non compatible"
On the contrary, Omar and Daniel's Wireless Circuit is purely based on pricniples of Electromagnetic Resonsnce, Electromagnetic Induction and Turns Ratio. The wireless electric circuit consists of Iron bars with Copper Turnings........"
The concept can be used to lighten the weight of an Formula 1 car and reduce expenditure on lightening of an aircraft using no wires.
This project they say is dedicated to Dr. Raja Ramanna, alumni of Bishop Cotton School. " He is a great visionary figure. The financial aid for the project was granted by Principal, Colonel John Ellis."
Omar and Daniel wish to research at top universities, and want more expore for this work. These 2 young boys are now working on a high-tech wheel chair, a solar powered car and are in process of developing nano-solar cells.