APPARATUS FOR CAPACITIVELY MEASURING CHANGES

• Main Author: Reime, Gerd
• Format: Patent
• Language: English; French; German
• Published: 26.09.2018
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; PULSE TECHNIQUE

An apparatus for capacitively measuring changes has a sensor (S) with a sensor-active region. The sensor has at least one transmitting electrode, which generates an electric field, and a further electrode (13) which is capacitively coupled to the transmitting electrode (15), wherein the transmitting electrode (15) is arranged between the further electrode (13) and an element (11) which is at a reference potential. An output of a driver/evaluation unit (5.0) is coupled to the transmitting electrode (15) and an input of the driver/evaluation unit (5.0) is coupled at high impedance to the further electrode (13), an electric field forming between the further electrode (13) and a reference potential on account of the electric field, generated by the transmitting electrode (15), between the transmitting electrode (15) and the further electrode (13). A change in the capacitance between the further electrode (13) and the reference potential is thus detected using the driver/evaluation unit (5.0). This provides a capacitive sensor which can be used to reliably detect changes in the sensor environment and is insensitive to a reference potential even in the case of a coating (18) or wetting (18).