People today own and use an increasing number of portable
electronic devices such as mobile phones, digital cameras, MP3
players or handheld computers. Each with its own battery and adaptor
for recharging. How much more convenient would it be if you didn’t
have to deal with all those different adaptors, connectors and
cables? But instead have a single wireless charging unit that would
keep all your portables powered up, so that you never miss an
important call on your mobile phone or that perfect shot with your
digital camera?
Wireless charging pad Philips Research is working on a wireless power system that is
very intuitive and convenient in use for charging mobile electronic
devices. It consists of a tablet, the size of a mouse pad, which
allows you to simply place your mobile device on it to charge it
–hassle-free with no cables or plugs to contend with. The wireless
charging pad can be used in the home or office but also in the likes
of hotel rooms or on trains and airplanes.
How does it work?
The charging pad uses the principle of magnetic induction, which is
also used for the current Philips electronic toothbrush. It consists
of a matrix of charger coils that can generate an alternating
magnetic field. The mobile devices contain a receiver coil in which
a voltage is induced. This voltage is used to power the device and
its battery. The transmitter and the receiver coil basically consist
of planar, spiral windings, typically made of printed circuit boards
(PCB) tracks.
High efficiency and low emission To enhance the efficiency of the system and to reduce the
emission of the magnetic field to a minimum, the transmitter coils
in the charging pad can be switched locally so that only those close
to a device on the charging pad are active. A sensor circuit is used
to detect where the device is placed on the charging pad. This means
that the charging pad can be scaled to any size, without loss of
efficiency.
Standardization To ensure that the power pad can charge all kind of portable
electronic devices from different brands, both the portable devices
as well as the charging pads have to comply with a universal
interface. For this reason, Philips is initiating cooperation with
other companies to develop a standard for this technology.