ONAXIS

Each magnetic encoder contains an integrated circuit that senses the angular position. The IC senses the angular position of a permanent magnet placed above it. The permanent magnet is diametrically polarized and of cylindrical shape.

Hall sensor technology detects the magnetic flux density distribution at the surface of the silicon. Hall sensors placed in a circular array around the center of the IC deliver a voltage representation of magnetic field distribution.

The sine and cosine voltage outputs from the sensor array vary with magnet position. The sine and cosine signals are then converted to absolute angle position with a fast flash interpolator.

This basic sensing technology can then be combined with further electronics to produce a wide range of output formats. Resolutions of up to 13 bit absolute (8192 counts per revolution incremental) are achieved with internal interpolation.

The ability of the encoder system to operate with a gap between the magnetic actuator and the encoder chip allows its incorporation into designs that need isolation of the moving elements.