Patent ID: 7085657

Claim:
A pressure switch comprising: i) a sensor element to supply an analog electrical signal corresponding to a pressure, ii) a signal processing unit which is connected downstream of the sensor element to amplify the analog electrical signal, and iii) a control unit for electrical switches which is connected downstream of the signal processing unit for switching external loads, for a display unit, for production interfaces and the like, wherein the signal processing unit comprises a chopper amplifier, which switches or balances the polarity of the analog electrical signal present at an input to the signal processing unit supplied by the sensor element, and the analog electrical signal present at an output of the signal processing unit, at the same clock rate, the output of the signal processing unit supplies a voltage with a magnitude corresponding to a measured quantity sensed by the sensor, and the output of the signal processing unit is connected upstream of an analog/digital converter which samples the voltage in a first phase and a second phase and converts them into numerical values and enables subtraction of the two values in a unit connected downstream the converter output.