Posts Tagged ‘wireless electricity’

More on Wireless Power

Friday, February 24th, 2012

Wireless Electricity

The most recent ATETV video introduces you to WiTricity; the Massachusetts based company known for producing wireless electricity. While you and I marvel at the possibilities, many products are already on the market and a few more are in development.

#1- Inductive Coupling
Anytime that an electrical current moves through wire, it creates a circular magnetic field around the wire. Bending this wire in a coil amplifies this field and the more loops in the coil, the bigger the field. If you then introduce a second wire into the magnetic field you have created, the electrical current will transfer. Simply put, inductive coupling then is the process of using magnetic fields to stimulate movement of a current through a wire.

According to a recent article in Fast Company Magazine, this is the first wireless powering system to market. “It 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 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 that then flows in that secondary coil charges the device’s onboard rechargeable battery.”

Products include:
Automotive: Companies like Powermat sell these pads and offer wireless solutions to among other industries, the automotive industry to integrate this technology into new cars. Imagine being able to recharge your cell phone, while driving simply by placing it strategically somewhere in the car itself? No cords necessary!

Flashlights: By eliminating exposed metal conductors and the need for unnecessary cords, the Reference ATEX Certified Explosion Proof Torch and Charger uses induction technology to eliminate some of the previous issues that oil and gas industry professionals previously encountered with hand held flashlights.

Cell Phones: HP has created the Palm USA using HP Touchstone Technology. “Charge on Contact. Simply. Magnetically. Intelligently.” – the Web-site announces.

#2- Radio Frequency Harvesting
While less efficient, they work across distances of up to 85 feet. In these systems, electricity is transformed into radio waves, which are transmitted across a room, then received by so-called power harvesters and translated back into low-voltage direct current. In marketable products, 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.

Products include:
This method of transmitting wireless power is not without its problems still which makes the number of products on the market available, scarce. But at Powercast in PA, you can purchase receivers and transmitters to customize your power solutions.

In the future, this will be available to consumers in the form of a few small appliances like clocks and smoke detectors and wireless sensors; down the road, it will appear in wireless boxes into which you can toss any and all of your electronics for recharging.

#3- Magnetically Coupled Resonance
WiTricity Technology uses magnetic resonance to transfer power over large distances. Following principles similar to the idea of acoustic resonance, which allows an opera singer to break a glass across the room by vibrating it with the correct frequency of her voice’s sound waves, magnetic resonance can launch an energetic response in something far away. According to Fast Company, the difference in this case is that “the response is the flow of electricity out of the receiving coil and into the device to which it’s connected. The only caveat is that receiving coil must be properly “tuned” to match the powered coil, in the way that plucking a D string on any tuned piano will set all the D strings to vibrating, but leave all other notes still and silent.”

Products in development:
Still under wraps!

A few years ago, Marin Soljačić, an assistant professor of physics at MIT, was dragged out of bed by the insistent beeping of a cell phone. “This one didn’t want to stop until you plugged it in for charging,” says Soljačić. In his exhausted state, he wished the phone would just begin charging itself as soon as it was brought into the house. So Soljačić started searching for ways to transmit power wirelessly. His efforts are clearly paying off. While the rest of us are still contemplating the possibilities of a world without cords, batteries, plugs, etc he is one of a few select individuals that are already hard at work turning these ideas into reality. As a result, the future of the electronics industry looks pretty bright!