23 Jul 2024


Magnetic absolute encoder is ‘the first’

The German sensor specialist Lenord + Bauer claims to have developed world’s first high-resolution, magnetic, absolute encoder. The company’s GEL 235 encoder (shown below) is said to combine the precision and accuracy of optical technology, with the robustness of an all-metal construction.

Lenord + Bauer magnetic encoder

The tough encoder uses a new type of contour disk made of ferromagnetic steel with three incremental tracks with stepped ridges etched into it using optical lithography and chemical etching processes. These tracks are scanned magnetically by magneto-resistive sensors which produce sinusoidal signals corresponding to the ridge positions, whose phase relationship is unique within a single revolution. The absolute position is determined by applying a Vernier scale to the readings.

The encoder is accurate to 0.1 of a degree and has a resolution of 28 bits (16-bit single turn and 12-bit multi-turn). The magnetic sensing technology is said to immune from the effects of ageing, temperature variations, condensation, dirt, vibration or impacts.

The 58mm-diameter encoder is available in single- or multi-turn versions with an SSI interface and a sine/cosine output signal. Plug-on adaptors are available for the Profibus DP and CANopen bus systems.

The encoder is available in the UK from Stockport-based Motor Technology.