PowerMat is an exciting new wireless charging technology. It was first shown in 2008 and early 2009 and is now available to purchase for home and office use.
So what is PowerMat? It’s a small device that uses wireless charging to charge your most important devices like cell phones (including iPhone and Blackberry), video games (including Nintendo DS), and iPods without having to plug them into 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 everything is wireless from then on. 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 across a conductor placed 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 say it is that it is a means of transferring electrical energy using a shared magnetic field.
Consider this arrangement:
1. Put electrical energy into a coil of wire
2. This will produce a magnetic field around the coil which will affect any metal within the field (as demonstrated by Faraday)
3.Change the field rapidly over time and an electric current will be generated in the metal
So what happens when a PowerMat is charged is that it generates rapidly changing magnetic fields on the mat; these are converted by receptors in any device on the mat into electrical energy, and thus these devices are charged. Magnetic fields and electrical currents are of course very small and can therefore function in wearable devices without posing a health risk to humans.
The same technology is used in a host of other devices and systems, including generators, motors, transformers, some cookers, induction brazing, etc. Perhaps the most familiar example to most people is that of rechargeable electric toothbrushes, where they are familiar with dropping a toothbrush onto a “dock” every day to keep it charged. However, they may not know that similar systems also work on electric guitar pickups, video cassette 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 soon see it in many other applications and products. The PowerMat company itself plans to extend the technology and feature it on kitchen counters, walls and other surfaces in the home. One day this technology can be used everywhere and be invisible, it will be so common. We will finally be freed from the endless tangle of chargers and cables around the home.