Magnetics Business & Technology - May/June 2022 - 10

FEATURE ARTICLE
QuattroMag and EnDra Technologies by Wachendorff Enable Precise Encoders
for Rugged Conditions
sensor, even when de-energized since it utilizes energy harvesting
from the rotation. Here too, a patented process enables
precise and reliable signal processing.
" In combination, these two technologies
are almost unbeatable for mobile applications, "
according to Steffen Negeli,
product manager. " Because it is contactless
and enclosed in housing, it's
wear-free and also has no moving parts
such as gears, he explains. " Paired
with the fact that the encoder doesn't
have a battery makes it completely
maintenance-free. They work reliably
and are temperature-resistant in ice or
in the desert, and are available also in
an offshore version able to withstand
marine environments. "
EnDra multi-turn technology
Using two core magnetic technologies to compete with the
precision of optical encoders yet withstand intense mechanical
vibration, automation manufacturer Wachendorff continues
to see its WDGA line of absolute encoders put to the test by
mobile equipment and industrial machinery designers. At the
heart of this success are the company's QuattroMag and EnDra
technologies which enable the performance of a diverse array
of robust equipment such as cranes, mobile work platforms and
even horizontal drilling equipment, shown above.
QuattroMag single-turn technology is based on four Hall sensors
used together with a patented calculation algorithm which
calculates the magnetic field generated by a diametrically split
magnet mounted on the face of the encoder shaft in such a way
that any interference between the Hall signals cancels each
other out. It can measure angular position more accurately
and quickly than conventional sensors in high-precision and
dynamic applications which in the past were exclusively the
province of optical systems.
EnDra stands for energy wire. A Wiegand wire consists of a
hard magnetic sleeve and a soft magnetic core. If the field of
the magnet moves along the Wiegand wire by rotating the shaft,
the soft magnetic core is forced to follow the field, constrained
by the hard magnetic sleeve.
An increasingly greater field difference is created in the wire, for
example, when tensioning an arc. As soon as the external field
reaches the coercive field strength of the sleeve, the sleeve is
demagnetized, and the built-up voltage of the core suddenly
jumps over. This pulse, which is independent of the speed, is
generated twice per revolution and converted into electrical
pulses using a coil. These pulses generate enough energy to
operate a low energy FRAM memory and provide information
on the number of revolutions.
Background - precise and reliable measurement in drives and
mobile machines
For more than 40 years, Wachendorff has been offering sensors
and automation products for mobile machines and industrial
vehicles. Just over ten years ago, the company developed the
series of absolute encoders that offer enormous advantages,
not only over conventional encoders, but also over conventional
sensors, such as potentiometers or simple angle sensors.
These enhancements make the products ideal for use in
outdoor applications, or in environments with high mechanical
demands such as mobile work machines, even aircraft elevators.
As
far as Wachendorff is concerned, only a magnetic solution is
good enough to meet both fundamental requirements, singleturn
to determine the number of steps and multi-turn for the
revolution counter. The WDGA encoders are considerably less
sensitive to vibrations which constantly occur in machines and
systems than in the case with optical absolute encoders with a
drive unit. Despite their compact design, the WDGA encoders
outperform optical systems with drive technology by a high factor,
the company says.
In addition, the multi-turn encoders are equipped with EnDra
technology which counts and stores revolutions via a Wigand
10 Magnetics Business & Technology * May/June 2022
www.MagneticsMag.com
Steffen Negeli,
product manager
http://www.MagneticsMag.com
Magnetics Business & Technology - May/June 2022

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