Abstract
A differential transformer using cylindrical capacitors is proposed in this work. Measuring capacitance changes to detect its displacement is the unique point of this sensor since most of such sensors are consist of electromagnetic coils and detect its flux change. This study has conducted to investigate the possibilities of improvement in response frequency and of decreasing instability of zero point caused by a magnetic body movement, by replacing the function of coils consisting of a differential transformer by capacitors. First, it is shown that the same composition as a differential transformer can actually be realized by capacitors. Secondly, non-linearity errors of sensors are reduced by increasing the number of electrodes. The developed sensor exhibit a linearity equivalent to a differential transformer and an excitation frequency of 39 kHz, which is about 10 times as high as that of a differential transformer.
