Cords and cables have been a reality for consumer devices since
the advent of home electronics. That reality may be changing very
soon, however, as a number of companies continue to make inroads
into eliminating the wires that keep our gadgets tethered to a
walland to one another.
Powercast, a new Pennsylvania-based startup says its solution for
wireless power harvesting is not only reliable, FCC-approved, and
safe, but is also ready to debut in millions of small devices by
the end of 2008, according to John Shearer, Powercast's founder and
chief executive.
The technology? Radio waves, the same technology driving cellular
phones and your FM dial.
Whether it's the promise of short-range wireless technologies like
ultra wideband (UWB), wireless USB, and the wireless
high-definition interface (WHDI) that transmit data from one device
to another, or methods for supplying those devices with power, such
as induction -- or now, RF -- the future home looks to be
increasingly cordless.
"Basically, we've developed a chip on the transceiver and receiver
side that efficiently transmits RF energy," said Keith Kressin,
executive vice president of sales and marketing for
Powercast.
While Kressin admits that using RF energy to power electronic
devices isn't a particularly new idea, he says his company's
patented approach is unique in that it can harvest much more of
that energy (50-70 percent) than traditional methods, typically 10
percent, according to the company.
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Because radio waves are in fact energy, they are already used to
send and receive cell phone, television, radio, and Wi-Fi signals
every day, he explained. Those waves spread out in all directions
until they reach an antenna that is tuned to the appropriate
frequency.
Powercast's wireless power platform uses a "Powercaster"
transmitter circuit running on conventional current to broadcast a
low-power radio signal at a predetermined frequency. The smaller
"Powerharvester" receiver circuitwhich can be embedded in any
low-power devicethen uses that energy to recharge or can even
replace the device's battery, according to Kressin.
The Powercast solution is able to maximize power transfer by using
a much broader area of the RF spectrum, the 900-MHz band. While not
necessarily a replacement for a conventional charger, the
technology will be able to "trickle charge" a variety of
electronics over a period of time so that their energy is never
fully depleted.
As with a traditional AM/FM radio, the closer one is to the tower
transmitting the signal, the better the reception. Powercast's
wireless platform operates using a similar principle.
According to the company, the wireless power platform can harvest a
few milliwatts of energy within a meter of the source, in this case
the transmitter. That is enough energy to charge a single depleted
cell phone battery about half way overnight, according to
Kressin.
The solution will also be ideal for devices with small batteries
such as watches, hearing aids, wireless keyboards and mice, and
game controllers, said Kressin, all of which could be continuously
charged.
But there are limits to the charging capabilities the Powercast
platform. Larger devices such as laptops will not be able to make
use of the company's solution simply because they require too much
power. In fact, the size limit for now seems to be at the cell
phone level for effective charging, company executives said.
During Powercast's demo at this year's CES, two prototype light
sticks equipped with LEDs from Philips were shown using the
company's new technology. According to Kressin, Philips will be the
first company to ship products using the wireless power platform
later this year.
"They're developing a lighting application, something you can do
with small LEDs," he said. "In this form, you're just powering,
though, and not charging. But I'm tracking about 20 major
categories of devices where our solution would be viable. We're
also talking to many companies that are now interested in
developing prototypes."
While a spokesman from Philips was not immediately available to
comment on the forthcoming lighting product, Govi Rao, the
company's vice president and general manager of solid-state
lighting, said "the technology could revolutionize what we know
about power" in a recent interview with Business 2.0
magazine.
Of course, Powercast isn't the only company working on wireless
energy transfer. Arizona-based WildCharger, who also demonstrated
its technology at this year's CES, is currently developing a line
of charging pads that can wirelessly transfer power via direct
contact between a smaller adapter fitted on a device and the pad
itself, using what's known as direct induction.
Induction is basically the same technology that charges your
electric toothbrush, and 'inductive coupling,' as its known, uses
the magnetic fields that are an innate part of any current's
movement through wire.
When a current moves through a wire, it creates a circular magnetic
field around the wire. By bending the wire into a coil, this can
amplify these magnetic fields. The more loops the coil makes, the
bigger the field will be. And while the pad itself has to be
plugged into a wall socket, it will supply a steady stream of power
to devices placed anywhere on top of it.
WildCharger says its 15 x 40 cm pads will come in 90-watt
capacities and will be able to charge large devices like laptops,
BlackBerries, and cell phones simultaneously.
Another solution comes from Fulton Innovation and its new eCoupled
technology.
eCoupled also makes use of intelligent induction, but is designed
to be embedded in circuitry in common household and everyday
objects like countertops, cabinets, carrying bags, car dashboards,
and consoles, the company says. The circuitry will then communicate
with the receiving coil that can be built into common consumer
electronics devices like laptops, cell phones, music players, and
gaming devices.
When someone places an eCoupled device on an eCoupled-ready
surface, the base will automatically recognize the relationship
between the device itself and base and will compensate and adapt
based on its charging needs.
As with all wireless communication technologies, consumers can
expect to see a variety of complimentary wireless charging
solutions emerge onto the market in the next few years.
Kressin says that in all likelihood, Powercast's wireless energy
solution will not be competing with other technologies like
induction, but would rather be used in conjunction with them.
"I really see our Powercast solution as complementary to induction
charging," Kressin said. "The pros of induction are that it is more
efficient and can transfer more power. If you're going to charge
something much bigger, like a laptop, that's your solution."
But induction also has its drawbacks, Kressin said. "The power
rolls off at a very small distance
and the size, expense, and
weight of the coils used in induction are prohibitive. I definitely
don't want to argue we're better, but for applications that use a
small battery, we certainly think we have the answer."