PowerMat is an exciting new wireless charging technology. It was first demonstrated in 2008 and early 2009 and is now available to purchase in the home and office.
So what is PowerMat? It’s a small device that uses wireless charging to charge your most important devices like cell phones (including the iPhone and Blackberry), video games (including the Nintendo DS), and iPod without you having to connect them to a charger or plug them into the wall. The PowerMat itself is of course plugged into the wall and connected to the mains via a cable, but from then on everything is wireless. You drop your device into the PowerMat and it charges wirelessly, without you having to do anything.
So how does PowerMat wireless charging work?
The technology behind PowerMat is known as ‘electromagnetic induction’ (or simply ‘magnetic induction’). Michael Faraday is generally credited with discovering the phenomenon of induction in 1831, although others were working in the same field at the time.
This electromagnetic induction is officially defined as “the production of voltage through a conductor in a changing magnetic field or a conductor moving through a stationary magnetic field,” but that doesn’t mean much to most people. A better way to put it is that it is a means of transferring electrical energy using a shared magnetic field.
Consider this arrangement:
1. Put electrical power into a coil of wire
2. This will produce a magnetic field around the coil that will affect any metal within the field (as Faraday demonstrated).
3. Change the field rapidly over time and an electric current will be generated in the metal.
So what happens when a PowerMat is charging is that it generates rapidly changing magnetic fields on the mat; These are converted by receivers in any device on the mat into electrical energy, and thus these devices are charged. Magnetic fields and electric currents are, of course, very small, so they can work in portable devices without posing a risk to human health.
The same technology is used in a host of other devices and systems, including generators, motors, transformers, some cookers, induction welding, etc. Perhaps for most people, the best-known example is rechargeable electric toothbrushes, where they are familiar with dropping a toothbrush onto a “spring” every day to keep it charged. However, they may not be aware that similar systems are also operating on electric guitar pickups, video tape players, and computer graphics tablets.
PowerMat is currently the best known example of a wireless charger but this technology is developing rapidly and we will see it in many other applications and products soon. The PowerMat company itself plans to extend the technology and present it on kitchen countertops, walls, and other surfaces in the home. One day, this technology will be able to be used everywhere and it will be invisible, it will be so common. Finally, we will free ourselves from the endless tangle of chargers and cables around the house.