A capacitive switch includes a drive circuit, a detection circuit, a reference circuit and an identification unit. The drive circuit outputs a drive signal and a switching signal, wherein the drive signal is outputted to a first node and a second node. The detection circuit is sequentially coupled to the first node and the second node according to the switching signal and generates a first detection signal according to the drive signal. The reference circuit is sequentially coupled to the second node and the first node according to the switching signal and generates a second detection signal according to the drive signal. The identification unit includes a first input terminal and a second input terminal respectively coupled to the first node and the second node, and identifies a phase shift between inputted detection signals received by the first input terminal and the second input terminal.

An assembly for connecting a flat body to a voltage supply is presented. The assembly includes a ribbon cable, a control unit, and a connection element. A voltage supply supplies an electric voltage to the control unit. The flat body includes an electrically conductive structure, and a switching surface for generating a control signal that is received by the control unit. According to one aspect, the control unit is embedded in an insulating material between the flat body and the connection element. Also presented is a flat body with such an assembly, as well as a method for producing such an assembly.

A proximity sensor assembly is provided that includes a proximity sensor comprising conductive circuitry and generating a signal based on a sense activation field. The proximity sensor assembly also includes control circuitry for processing the signal to sense activation of the sensor, the control circuitry further monitoring the signal and comparing the signal to one or more parameters of a prior captured signal stored in memory and determining a fault condition based on a change between the current signal and the one or more parameters of the prior signal, wherein the control circuitry generates a baseline value of the prior signal and adjusts the baseline value to an adjusted baseline value when a fault condition is detected in an attempt to correct the fault condition.

A sensor circuit and method. The circuit includes a first subcircuit that includes a first sense capacitor, a first integration capacitor, and a first clock input for receiving a first digital clock signal for initiating discharge of the first integration capacitor at time T. The circuit includes a second subcircuit that includes a second sense capacitor, a second integration capacitor, and a second clock input for receiving a second digital clock signal for initiating discharge of the second integration capacitor at time T+T.sub.d. A rate of discharge of the first and second integration capacitors is at least partly determined by a capacitance of the first and second sense capacitor, respectively. At time T.sub.eval, after initiation of discharge of the first and second sense capacitors, the extent to which the first and second integration capacitors have discharged is compared. A digital signal indicating the result of the comparison is outputted.

A proximity sensor includes a sensor cable that includes a first electrode wire and a second electrode wire arranged parallel to each other, an insulation covering both the first electrode wire and the second electrode wire, and a shield partially covering a surface of the insulation so as to form an opening, the first electrode wire and the second electrode wire being arranged to have different distances to the opening, and a detector circuit that includes a first capacitance detecting portion for detecting a first capacitance to be detected by the first electrode wire, a second capacitance detecting portion for detecting a second capacitance to be detected by the second electrode wire, and a differential output portion for outputting a difference between the first capacitance and the second capacitance.

Disclosed herein are system, methods, and apparatus for low power capacitive sensors. Apparatus may include a timing block configured to generate a repetitive trigger signal having a first frequency, and further configured to generate a clock signal having a second frequency. Apparatus may also include a sensing block coupled with the timing block and configured to, in response to the repetitive trigger signal, detect a change in capacitance associated with an object proximate to a capacitive sensor button by applying an excitation signal to the capacitive sensor button during a measurement period. Apparatus further include a wake logic block coupled with the sensing block and configured to transition a processing unit from a first power consumption state to a second power consumption state in response to the sensing block detecting the change in capacitance associated with the object proximate to the capacitive sensor button.

An operator control device for a vehicle, and a method for operating such an operator control device is disclosed. The operator control device is for controlling safety-relevant functions. To this end, the operator control device has at least one user interface having at least one user input panel for user input and a sensor system for identifying a user input in the area of the user input panel, wherein the sensor system has at least one capacitive sensor device having a first, electrically conductive sensor structure and a second, capacitive sensor device having a second, electrically conductive sensor structure, the sensor structures being arranged beneath the user interface in the area of the user input panel. The first sensor structure and the second sensor structure are each configured in comb-like and/or meanderous fashion and arranged in intermeshing fashion at least in a subarea of the user input panel.

An evaluation circuit for a capacitive sensor for detecting the distance, speed, or position of an object, comprises a reference capacitance and a measuring capacitance. A square wave voltage is applied to the reference capacitance and the measuring capacitance via a resistor, and a pulse which has a variable duration is obtained with the aid of a logic linking unit. The reference capacitance is connected to a first switching stage and the measuring capacitance is connected to a further switching stage. A single measuring capacitance has a capacitive coupling to an auxiliary electrode, and the switching stages are part of a logic linking unit. An output of the logic linking unit is connected to an integration stage. A charging capacitor (Ca) is charged or discharged via an output of the integration stage.

A capacitive proximity sensor including a detection circuit, including a detection capacitor, a storage capacitor and switches, a DC voltage generator and a microcontroller which is configured to control the switches and to: obtain a voltage value across the terminals of the storage capacitor and across the terminals of the detection capacitor; calculate a first average defined by the average of the voltage values which are obtained at the end of each iteration of a first acquisition phase and a second average defined by the average of the voltage values at the end of each iteration of a second acquisition phase; and detect a human presence when the difference between the first average and the second average is above a predefined detection threshold.

In one embodiment, a device includes one or more processors and one or more memory units. The one or more memory units collectively store logic configured to cause the one or more processors to perform operations including obtaining a first measurement associated with a first voltage, the first voltage output by the mutual-capacitance measurement circuit in response to a first change in capacitance, and obtaining a second measurement associated with a second voltage, the second voltage output by the mutual-capacitance measurement circuit in response to a second change in capacitance. The operations further include calculating a differential measurement using a difference between the first measurement and the second measurement and determining whether a touch or proximity event has occurred based at least in part on the calculated differential measurement.