Capacitive Positioning Device

摘要

A positioning device for capacitively detecting an object enclosed in a medium comprises a measuring electrode, a reference electrode, and a receiving electrode. The measuring electrode with the receiving electrode forms a measuring capacitance, which can be influenced by the object. The reference electrode with the receiving electrode forms a reference capacitance, which cannot be influenced by the object. The positioning device further comprises an oscillator configured to supply the measuring capacitance and the reference capacitance with phase-shifted AC voltages and a control device configured to control amplitudes of at least one of the AC voltages, in order to adapt effects of electrical fields of the measuring electrode or of the reference electrode on the receiving electrode to one another. The measuring, reference, and receiving electrodes are planarly formed. The measuring electrode has a larger surface area than the reference electrode.

主权项

1. A locating appliance for capacitive detection of an object enclosed in a medium, comprising:
a measurement electrode; a reference electrode; a reception electrode, the measurement electrode and the reception electrode configured to form a measurement capacitance that can be influenced by the object, and the reference electrode and the reception electrode configured to form a reference capacitance that cannot be influenced by the object; an oscillator configured to supply the measurement capacitance and the reference capacitance with phase-shifted AC voltages; and a control device configured to control amplitudes of at least one of the AC voltages in order to match influences of electrical fields from the measurement electrode and the reference electrode on the reception electrode to one another, wherein the measurement electrode, the reference electrode, and the reception electrode are in two-dimensional form, and wherein the measurement electrode has a greater area content than the reference electrode.