Abstract: The invention relates to a sensor device, particularly a limit or threshold value sensor device with a sensor system for detecting an external measured quantity, a switching device being provided for switching a load circuit. The known design of the switching device by means of transistors or electromechanical relays has always necessitated compromises with regards to the electronic functionality, design of the circuit and arrangement on or with the sensor device. The solution provided by the invention is a switching device with an almost wattless drive and galvanic separation or isolation between the control circuit and output circuit, the sensor system being constructed independent of the load circuit.

Abstract: A protective circuit for limiting the voltage for a device to be protected, particularly a load with an upstream-connected voltage and current limiting device. The device to be protected is provided in an output circuit of the protective circuit and is separable by means of a switching element, a voltage detector being provided with an electronic switch on the one hand and a voltage sensor on the other. The control terminal of the electronic switch is in electrical operative connection with the voltage sensor. A microdevice with a control circuit is provided, the microdevice having the switching element and being designed with a high input resistance of the control circuit. The control circuit is galvanically separated from the output circuit and switchable by the control circuit. The output circuit in the opened state has a galvanic separation of its output terminals.

Abstract: The invention relates to a sensor device, particularly a limit or threshold value sensor device with a sensor system for detecting an external measured quantity, a switching device being provided for switching a load circuit.

Abstract: The invention relates to a protective circuit for limiting the voltage for a device to be protected, particularly a load with an upstream-connected voltage and current limiting device, the device to be protected being provided in an output circuit of the protective circuit and is separable by means of a switching element, a voltage detector being provided with an electronic switch on the one hand and a voltage sensor on the other and the control terminal of the electronic switch is in electrical operative connection with the voltage sensor. A microdevice with a control circuit is provided, in which the microdevice has the switching element and is designed with a high input resistance of the control circuit.