Trapped Charge Transducer for Low Cost Angular Position Sensing
Original Publication Date: 1981-Apr-01
Included in the Prior Art Database: 2005-Feb-11
Capacitive transducers are becoming increasingly of interest in stepper motor positional sensing for feedback. They provide low cost and reliable means of obtaining rotational position and rate feedback. The present structure provides for a novel trapped charge transducer, i.e., one in which the rotor substrate is a thin permanently polarized dielectric which has an electric charge trapped adjacent to the rotor conductor pattern. This layer eliminates the requirement for either a high voltage bias supply or a high frequency carrier.