This article elucidates how electronics devices (like mobile phones) can be ‘wirelessly’ charged. This article also enlightens ‘Wireless Power Consortium’ that aims at new industry standard for low-power ‘inductive charging’ called ‘Qi‘ (pronounced chee).
Inductive charging/wireless charging uses an electromagnetic field to transfer energy between two objects. This is usually done with a charging station. Energy is sent through inductive coupling to an electrical device, which then can use that energy to charge batteries or run the device.
Induction chargers typically use an induction coil to create an alternating electromagnetic field from within a charging base station, and a second induction coil in the portable device takes power from the electromagnetic field and converts it back into electrical current to charge the battery. The two induction coils in proximity combine to form an electrical transformer.
Greater distances can be achieved when the inductive charging system uses resonant inductive coupling.
- An early example of inductive power transfer is the crystal radio which used the power of the radio signal itself to power headphones. Some such radios can even use the power of a stronger station to increase the volume of a weaker station
- Transcutaneous energy transfer (TET) systems in artificial hearts and other surgically implanted devices.
- Oral-B rechargeable toothbrushes by the Braun company have used inductive charging since the early 1990s.
- Hughes Electronics developed the Magne Charge interface for General Motors. The General Motors EV1 electric car was charged by inserting an inductive charging paddle into a receptacle on the vehicle. General Motors and Toyota agreed on this interface and it was also used in the Chevrolet S-10 EV and Toyota RAV4 EV vehicles.
- In 2006, researchers at the Massachusetts Institute of Technology reported that they had discovered an efficient way to transfer power between coils separated by a few meters. The team, led by Marin Soljačić, theorized that they could extend the distance between the coils by adding resonance to the equation. The MIT wireless power project, called WiTricity, uses a curved coil and capacitive plates.
- At CES in January 2007, Visteon unveiled their wireless charging system for in vehicle use that could charge anything from cell phones to mp3 players.
- April 28, 2009: An Energizer inductive charging station for the Wii remote is reported on IGN.
- At CES in January 2009, Palm, Inc. announced their new Pre smartphone would be available with an optional inductive charger accessory, the “Touchstone”. The charger came with a required special backplate that became standard on the subsequent Pre Plus model announced at CES 2010. This was also featured on later Pixi, Pixi Plus, and Veer 4G smartphones. Upon launch in 2011, the ill-fated HP Touchpad tablet (after HP’s acquisition of Palm Inc.) had a built in touchstone coil that doubled as an antenna for their NFC-like Touch to Share feature .
- In August 2009: A consortium of interested companies called the Wireless Power Consortium announced they were nearing completion for a new industry standard for low-power Inductive charging called Qi
- Intel and Samsung plan to launch Qi wireless charging devices for phones and laptops in 2013.
- Nokia launched two smartphones (the Lumia 820 and Lumia 920) on 5 September 2012, which feature Qi wireless charging.
How It Works?? Watch video At: WPC