Direct measuring position encoder for axial transversal flux machine

The paper presents a direct measuring absolute position encoder for a previously unpublished axial transversal flux machine. It addresses requirements of encoders that are not sufficiently fulfilled with common encoders. The encoder is small in size and directly mounted in the machine. It contains no mechanical parts and measures the magnetic field of the permanent magnet disc rotor directly by digital hall elements. Therefore, the encoder is scaled referring to the pole pair number of the machine in the radial direction. The encoder works under any speed and load condition, which is especially important at zero to low speed, where sensorless methods have drawbacks. The paper explains the sensor and describes the analysis of the output, during idle operation and under full load.