Capacitive rotary position encoder and capacitive rotary position detection method

Abstract

Some embodiments may include a capacitive rotary position encoder for the absolute determination of a rotary position about a rotary spindle. The rotary position encoder may include a transceiver unit, comprising a first arrangement of N electrically conductive, capacitive sensitivity areas which are embodied as angle segments over a defined angle range, which are distributed uniformly over the circumference, an electrically conductive reference area and an evaluation circuit, by means of which an electrical capacitance value between the reference area and one of the sensitivity areas is determinable. In some embodiments the sensitivity areas and the reference area are embodied as conductor track structures on a first electronics printed circuit board. A counterpart may be situated opposite the transceiver unit and rotatable relative thereto about the rotary spindle and may include a reference coupling area arranged opposite the reference area, and an arrangement of electrically conductive code areas connected thereto.

Description

technical field [0001] The invention relates to a capacitive rotary position encoder and a method for capacitive rotary position determination. Background technique [0002] The invention relates in particular to the technical field of capacitive rotary position encoders, in which the overlapping of conductive areas separated with respect to one another by a dielectric and in this case varying said conductive areas varies with rotational position Rotational position is determined with the aid of capacitance values ​​between. According to a simplified theoretical model, in this case the resulting capacitance value is proportional to the area overlap ratio. [0003] In this case, in a rotary encoder, the conductive areas can be rotated contactlessly one above the other using an air gap as a dielectric, with the result that no mechanical wear of the sensor system occurs. In addition to gases such as air, rotary encoders of this type can also be operated with liquids as dielec...

AI Technical Summary

Problems solved by technology

Components for evaluating larger numbers of channels (e.g., 50 or more channels) are not used as standard, or require additional hardware expense due to multiplexer circuits, etc.

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