Wireless technology: wireless recharging

Wireless transmission of electricity has been understood in theory since the work of Nikolai Tesla in the 19th Century. Safe, efficient and cost-effective wireless electricity could hold countless benefits, from eliminating the need to install costly copper wiring to lowered reliance on batteries for small devices.

Inductive coupling (or other methods) is used to charge multiple cell phones, PDAs, MP2s, on a charging pad. Some United States companies currently manufacturing in this market include Powermat, eCoupled, WiPower and WildCharge. According to WiPower, inductive charging systems work with about 80% to 90% efficiency.

A charging pad that looks 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 as Faraday predicted, induces current to flow through a small secondary coil that's built into any portable device, such as a flashlight, a phone, or a BlackBerry. The electrical current flows in a secondary coil which charges the device's onboard rechargeable battery. There are endless opportunities for these Pads to be used in such places as offices, airports, public places and at homes.

Another invaluable application would be the use wireless electricity to power a security camera that doesn't get enough light from a solar cell alone. A scientist recently has demonstrated an unplugged Toshiba television set sitting 5 feet away and charging - wirelessly. Just think no more tangle of power cables or jumble of charging stations. This wireless power can also be used to light up fluorescent lighting tubes.

Radio frequency Harvesting electricity is transformed into RF can reach distances of 85 ft it is received by power harvesters and translated back into low voltage dc current. Other ideas like smoke detectors wall clocks small appliances, power tools could use this wireless electricity. Home automation is a product group area that is looking at this technology that could retrofit an energy inefficient home into an efficient home.

But wireless technology is not only neater, it's cleaner. The EPA says Americans purchase a total of 3 billion disposable dry-cell batteries every year (part of a worldwide market of about 15 billion) and then throw 2.8 billion of them into landfills. Wireless systems are designed for rechargeable batteries that can be reused hundreds of times before they become trash.

Magnetic coupling is particularly suitable for everyday applications because most common materials interact only very weakly with magnetic fields, so interactions with extraneous environmental objects are suppressed even further. "The fact that magnetic fields interact so weakly with biological organisms is also important for safety considerations.

However, despite the success of WiTricity, the technology has a long way to go before it is widely deployed commercially... not to mention the need to better understand side effects such as interference and possible effects on health and the environment.



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