Proximity sensors by POSITAL use the unique Wiegand power technologyDecember 16, 2020 REDWIRE is news you can use from leading suppliers. Powered by FRASERS.
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POSITAL-Fraba’s portfolio of solutions includes Wiegand sensors, which are tiny devices that use variations in an external magnetic field to generate electrical signals and energy. They have unique properties that make them an ideal choice among proximity sensors. Among their advantages are intrinsic safety, insensitivity to electrical noise, and consistent response.
The company offers each of these Wiegand sensors in a package with a 15-millimetre Wiegand wire surrounded by a copper coil, all in an SMD-mountable plastic support structure.
No replacement batteries required
These proximity sensors are constructed around small sections of Wiegand wire, a specially prepared ferromagnetic alloy with a unique physical property. When users expose them to alternating external magnetic fields, Wiegand wires retain magnetic polarity at first, but when the external field reaches a certain threshold, the polarity will reverse abruptly. Occurring within a few microseconds, this polarity switch can generate a distinct current pulse in a fine copper coil wrapped around the ferromagnetic core.
The pulse is sufficiently strong to activate logic circuits and can energize low-power electronic chips. With this self-powering ability, POSITAL Wiegand sensors are more reliable and safe, as they can provide signals for alarm systems without external power sources; users do not have to check or replace backup batteries.
There are several ways to use these proximity sensors. If the external object is magnetized or has small permanent magnets mounted on it, the sensor will respond with the object comes near enough to trigger the polarity reversal. This can be used to detect and measure linear or rotary motions. Users can also mount a sensor between a set of permanent magnets; when an iron or steel object comes close enough, it will distort the magnetic field instantly around the sensor enough to trigger the polarity flip and generate a current pulse.
With their self-powered characteristics, Wiegand sensors require no external power sources. No mechanical contact exists between the source of the alternating magnetic field and the Wiegand wire assembly, and there is no wear. Other advantages include long operational lifespan, physical ruggedness, and a wide temperature range.
For more information, contact POSITAL.