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on both contactless power and
contactless
data
technology,
which can easily connect (and
disconnect) over a short distance
without using any mechanical
contact, demonstrated in the ARISO
connectors from TE Connectivity.
To date, contactless, or wireless,
data has come in many forms,
from cellular to Wi-Fi, Bluetooth
and ZigBee; however, for low-data-
rate sensor data, these interfaces
have a lot of packet-processing
and network-interface and mesh
networking overhead. This costs the
designer, both in terms of real estate
and power consumption, as well as
direct component costs.
For its part, wireless power has
undergone a revolution of late,
thanks to the efforts of groups such
as the Wireless Power Consortium,
pushing Qi, as well as the now
merged Alliance For Wireless Power
and Power Matters Alliance. These
have developed standards for
the transmission of power levels
of up to 5 W, with a usable range
of up to 30 mm, to charge mobile
devices, particularly handsets. The
standards use variations of inductive
and resonant power at various
frequencies to achieve this, but all
require a relatively large footprint,
while also being relatively costly.
The trick is to find the sweet spot in
terms of data rates, cost and power
consumption for wireless data, and in
terms of range and cost for wireless
power, such that both interfaces can
fit within the confines of a typical
M30- or M12-type sensor head.
Thanks to the work that been done
to date in terms of RF function
integration to lower cost, as well as
increases in the efficiency of wireless
power transmission, this sweet spot
is attainable by matching the wireless
data and power transmission circuits
to the application’s low power and
short range requirements.
For data, the 2.45-GHz unlicensed
band was chosen as it can be
implemented using a near-field
antenna design with a simple loop
For power, the principle challenges
are integrating the power coils
and near-field antenna into a very
small form factor that is relatively
easy to manufacture. This requires
knowledge of mechanical design
and power electronics, as well as
magnetics, RF circuit design and
antennas.
With both the data and power
transmission now integrated into a
single connector head, the options
and application dynamics change,
dramatically. Flexibility jumps to
a higher level, with 360° rotation
without cable, connector, or harness
wear and tear. This freedom of
movement also allows for connector
tilt, angle or misalignment, while the
rotational freedom enables faster
maintenance-free rotation as well
as faster return to starting points,
as the rotating heads don’t have to
rotate back through 180° offset, but
instead can keep going to 360°.
Contactless connectors are vibration
resistant and are hermetically
sealed against harsh environments
and have unlimited mating cycles,
despite wet & dusty environments.
The magnetic coupling is particularly
attractive in gaseous applications or
where flammable liquids or material
are present.
Other advantages include easy
on-the-fly connection without the
traditional mechanical limitations,
design flexibility and cost savings
by enabling the transfer of power
and signal through fluids and walls,
as well as improved reliability for
reduced maintenance & lower total
cost of ownership.
For more information about the
ARSIO range of products from
TE, please visit the company's
site.
ARISO and TE Connectivity are
trademarks.
Figure 2: Free from the strictures of contact, contactless
interconnects provide greatly improved flexibility and reliability,
while magnetic coupling protects against explosions in gaseous
or otherwise flammable environments
Sensors
Special Edition
New-Tech Magazine Europe l 59