Abstract: An inductive power transfer system for the shaft mounted electronics of a rotary torque signal generating system includes a pair of planar PCB inductors formed by spiral copper traces on the planar surfaces of one or more layers of PCB substrate material. A primary inductor comprising a copper trace on a planar PCB substrate surrounds but is not connected to a steel torque transmission shaft. A secondary PCB trace inductor on another planar substrate is mounted for rotation with the shaft and in coaxial relation with both the shaft and primary inductor substrate so as to be inductively linked therewith.

Abstract: An inductive power transfer system for the shaft mounted electronics of a rotary torque application includes a pair of planar PCB coils having spiral copper traces on the surfaces of one or more layers of PCB substrate material. A primary coil surrounds but is not connected to a steel torque transmission shaft for rotation therewith. A secondary coil is mounted for rotation with the shaft and is inductively linked with the primary coil by means of a close proximity parallel mounting relationship wherein both coils are coaxial with the torque transmission shaft and use the shaft as a partial low permeability core.

Abstract: An optical system for wireless data communication between the sensor electronics on a rotary shaft and the fixed data processor is disclosed. A first ring carrying IR LEDs is mounted to rotate with the shaft. A second ring carrying a photodetector is mounted adjacent to the first ring but does not rotate with the shaft. In the disclosed embodiment, both rings have LEDs and a photodetector so data and/or information can be transferred both to and from the shaft.