Capacitive sensor for relative angle measurement

Based on a capacitive angle/angular speed sensor a sensor measuring the relative angle between two rotating shafts has been developed. Two rotatable grounded electrodes are placed between two sensor plates. The relative angle between the two rotors and the absolute position of the rotor blades are calculated from measurements of the capacitive coupling between different transmitting stator segments. A prototype of this sensor has been developed with a range of the relative angle of /spl plusmn/7.5/spl deg/ with a resolution of 0.1.