A capacitive sensing device comprises an antenna electrode for emitting an alternating electric field in response to an alternating voltage caused in the antenna electrode and a control and evaluation circuit configured to maintain the alternating voltage equal to an alternating reference voltage by injecting a current into the antenna electrode and to measure the current. The control and evaluation circuit includes a microcontroller with a digital output for providing a digital signal and a low- pass filter operatively connected to the digital output for generating the alternating reference voltage by low-pass-filtering the digital signal.
Capacitive sensing device
2016-02-10
Patent
Elektronische Ressource
Englisch
IPC: | G01D MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE , Anzeigen oder Aufzeichnen in Verbindung mit Messen allgemein / B60N SEATS SPECIALLY ADAPTED FOR VEHICLES , Sitze besonders für Fahrzeuge ausgebildet / B60R Fahrzeuge, Fahrzeugausstattung oder Fahrzeugteile, soweit nicht anderweitig vorgesehen , VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR / H03K PULSE TECHNIQUE , Impulstechnik |