Enhancing robustness of a new capacitive/magnetic full turn absolute angular sensor

In order to reduce the influence of axial displacement, certain capacitive angular sensors use a symmetric design that limits their absolute measuring range to 180°. This paper presents a combined sensor that utilizes a Wiegand sensor to obtain additional information needed to resolve 360°. Since magnetic and electric fields required by the sensing principles do not interfere, one single rotor design can be used for both fields. When the receiver coil on a Wiegand sensor has to drive a current, this current influences the shape and duration of the pulse generated by the sensor. We found that shape and amplitude of the pulse vary depending on the strength of the applied fields and the location of the initial inverse nucleation. However the stability of the pulse amplitude and the pulse duration are important for the robustness of the sensor. A modified Ising model that simulates the domain wall propagation is presented and results of measurements and numerical simulations are reported.