|
Wireless Charging: Almost Ready For Prime Time
(Mobile Development and Design Via Acquire Media NewsEdge) How many chargers do you own If you have a cell phone, laptop,
tablet, camera, GPS, and other portable devices, you probably have
quite a few and have even lost some of them. Still, you may
want to add one more to the list. Wireless chargers have been
around for a little while now, but the technology is starting to
take off.
Wireless chargers plug into the ac outlet, but you don’t
plug your device into them. Instead, you simply put your device on
top of the flat surface. The charger has a coil that acts as a
transformer primary winding and generates a magnetic field. The
device that’s getting charged also has a built-in coil that
becomes the transformer’s secondary winding. The magnetic
field induces a voltage into the secondary winding, and that
voltage is then rectified into dc and used to charge the
device’s battery.
The wireless chargers on the market so far aren’t too
popular. Most mobile devices don’t have a built-in secondary
coil, so you have to put them into a special sleeve that has
one so much for the convenience and low cost of wireless
charging. In addition, you have to carefully align the coils to get
maximum coupling between them to get enough transferred power for
charging. It’s a nuisance at best. Is this any more
convenient than just plugging in a charger
The Industry Investigates
Still, the industry is moving to adopt some form of wireless
charging for cell phones. Three groups have released specifications
and standards:
The Power
Matters Alliance, including AT&T, Google, Starbucks, and
others The Wireless Power Consortium, including LG, Motorola,
Nokia, Energizer, and othersThe Alliance for
Wireless Power, including Samsung and
others With no industry agreement on one approach, it’s difficult
to see where this will end up. All the approaches are different and
incompatible. My guess is that we will see multiple standards
coexist unless the industry suddenly decides to coalesce around one
of them. What will Apple do We shall see.
The biggest issue is spatial freedom, or not having to precisely
align the phone and the charger coils. They need to be close but
not so perfectly aligned, which is hard to do magnetically. I saw a
capacitive coupling method developed by Murata at last year’s
CES that is better in that regard, but none of the standards are
using it.
Intel is also working on wireless charging, enabling you charge
your cell phone from your laptop. It uses resonance at higher
frequencies in the inductive coils to boost the range and power of
the magnetic fields. Integrated Device Technology (IDT) has
developed a chipset for this technology, but it is incompatible
with all the other standards.
Power by
Proxi, a New Zealand company, is trying to develop patents from
the University of Auckland. It owns 125 patents in this field as
well as more than 900 claims developed over years of research and
development. The company’s first developments involved
charging electrical vehicles like forklifts, golf carts, and other
industrial and construction equipment. It also developed wireless
couplings that go between the rotating joints of blade motors on
wind generators and the generator itself without slip rings.
Recently, Power by Proxi turned its attention to cell phones. So
far, it has developed a wirelessly chargeable AA cell. The cell
phone can be oriented in any position inside the charging box
(see the figure). It operates at 500 kHz and is
loosely coupled, probably using resonance. It’s one more
technology to deal with, but Power by Proxi could be a major player
with its killer IP portfolio.
I’m not sure this format fits everyone. You have to have
the charger pad, which is likely larger than your regular charger.
Furthermore, unless airports, hotels, restaurants and other places
install them, you still need an ac outlet. Hopefully, phones with
wireless chargers also will still be able to plug into standard
chargers.
© 2012 Penton Media
[ Back To LatinAmerica.tmcnet.com's Homepage's Homepage ]
|
Internet Telephony Magazine
Click here to read latest issue
CUSTOMER 
Cloud Computing Magazine
Click here to read latest issue
M2M Evolution Magazine
Call Center/CRM
Info Tech 
IP Communications 
Mobile 
Green 
Satellite 
Robotics 
