The POSITAL IXARC UCD-S101G-1212-V6SA-2RW Magnetic SSI with Preset encoder is robust, durable and compact. Its battery and gearless construction makes it mechanically simple and economical as compared to optical encoders. A Aluminum flange, Steel housing and wide temperature range of void make it appropriate for many applications. A compact Blind Hollow, ø 36 mm / ø 42 mm flange can be used in applications with very limited installation space. Using an innovative technology keeps track of the number of rotations that the encoder has experienced, even if the rotations occur when there is no system power. To accomplish this, the encoder generates electrical energy from the rotation of the encoder shaft. The technology is based on the ‘Wiegand effect’: when a permanent magnet on the encoder shaft rotates through a certain angle, the magnetic polarity in a ‘Wiegand wire’ suddenly changes, inducing a brief voltage spike in a coil surrounding the wire. This pulse both marks a rotation of the shaft and powers the electronic circuitry that records the event. The Wiegand effect occurs reliably even with very slow rotations and eliminates the need for backup batteries.