A circuit system includes: a receiver circuit which outputs a periodic voltage pulse via a bus line; and an ascertaining device configured to ascertain whether the voltage on the bus line has reached a specified threshold value. The circuit system is configured to start the reception of data signals a specified time period after an instant at which the voltage on the bus line has reached the specified threshold value.

A power semiconductor module includes a power electronics circuit and a measuring circuit for measuring a physical parameter occurring in the power electronics circuit and for providing a corresponding measurement signal. A transmission circuit is coupled to a secondary side of a transfer unit, and an evaluation circuit is coupled to the primary side and galvanically isolated from the transmission circuit by the transfer unit. The evaluation circuit supplies an AC voltage to the primary side, causing primary current to flow on the primary side, which in turn results in secondary current on the secondary side, the secondary current being supplied to the transmission circuit. The transmission circuit receives the measurement signal and modulates the secondary current in accordance with the measurement signal, which results in a modulation of the primary current. The evaluation circuit evaluates the modulation of the primary current and generates an output signal dependent thereon.

A power semiconductor module includes a power electronics circuit and a measuring circuit for measuring a physical parameter occurring in the power electronics circuit and for providing a corresponding measurement signal. A transmission circuit is coupled to a secondary side of a transfer unit, and an evaluation circuit is coupled to the primary side and galvanically isolated from the transmission circuit by the transfer unit. The evaluation circuit supplies an AC voltage to the primary side, causing primary current to flow on the primary side, which in turn results in secondary current on the secondary side, the secondary current being supplied to the transmission circuit. The transmission circuit receives the measurement signal and modulates the secondary current in accordance with the measurement signal, which results in a modulation of the primary current. The evaluation circuit evaluates the modulation of the primary current and generates an output signal dependent thereon.

A method for protecting a nonmobile work machine driven by an electric motor includes determining, via a measuring unit, at least one measured value of a time-critical parameter of the work machine. The work machine is switched off when the determined measured value of the time-critical parameter is outside a predefined setpoint range. The determined measured value of the time-critical parameter is quantized in a level signal and transmitted as a first signal to an evaluation unit via an interface, and a second signal for further information concerning the work machine, to be transmitted from the measuring unit to the evaluation unit, is modulated to the first signal.

The present invention provides a power supply controlling module, which is suitable for a power supply controlling device. The power supply controlling device comprises a power source and a plurality of connecting ports. The power supply controlling module comprises a plurality of control units and a resistance. Each of the control units respectively connects with each of the connecting ports. The control units comprise a first control unit and at least one second control unit. The resistance electrically connects with the control units. The first control unit comprises a detecting circuit and a first control circuit, which respectively connects with the resistance. Each of the at least one second control unit comprises a second control circuit, which respectively connects with the resistance.

An apparatus for monitoring at least one physical or chemical process variable, comprising at least one sensor unit and an electronics unit for signal registration, evaluation and/or feeding, wherein the sensor unit is operated with alternating electrical current and/or communication between the electronics unit and the sensor unit occurs with alternating electrical current and/or alternating voltage. An explosion protection circuit with intrinsic safety, which includes a safety barrier, which has at least one unit for electrical current- and/or voltage limiting, is provided within the explosion protection circuit a unit for impedance matching, which unit for impedance matching includes at least one transformer.

An apparatus for monitoring at least one physical or chemical process variable, comprising at least one sensor unit and an electronics unit for signal registration, evaluation and/or feeding, wherein the sensor unit is operated with alternating electrical current and/or communication between the electronics unit and the sensor unit occurs with alternating electrical current and/or alternating voltage. An explosion protection circuit with intrinsic safety, which includes a safety barrier, which has at least one unit for electrical current- and/or voltage limiting, is provided within the explosion protection circuit a unit for impedance matching, which unit for impedance matching includes at least one transformer.

A module having an input configured to connect a sensor and having an indicator configured to optically indicate a physical state of the sensor. The module is configured to transmit a logical signal associated with the physical state or an inverted logical signal of the sensor to a higher-level unit and to receive a control value from the higher-level unit. The module is configured to evaluate the control value and to determine, on the basis of the control value, whether the value of the logical sensor signal or the inverted logical sensor signal is to be used for the optical indication of the physical state of the sensor.

A field device coupling apparatus for coupling a field device to a higher-level controller, including a current interface with a first interface connection point and a second interface connection point, with which interface connection points the field device coupling apparatus can be connected to the higher-level controller in order to receive an interface current, further including a load circuit connected between the first interface connection point and the second interface connection point, the load circuit including a controllable load and being adapted to provide a supply voltage for the field device using the controllable load based on the interface current, wherein the load circuit includes an AC negative feedback path, which runs from an output branch of the load circuit to an input terminal of the controllable load and serves to increase the AC impedance between the first interface connection point and the second interface connection point.

A field device coupling apparatus for coupling a field device to a higher-level controller, including a current interface with a first interface connection point and a second interface connection point, with which interface connection points the field device coupling apparatus can be connected to the higher-level controller in order to receive an interface current, further including a load circuit connected between the first interface connection point and the second interface connection point, the load circuit including a controllable load and being adapted to provide a supply voltage for the field device using the controllable load based on the interface current, wherein the load circuit includes an AC negative feedback path, which runs from an output branch of the load circuit to an input terminal of the controllable load and serves to increase the AC impedance between the first interface connection point and the second interface connection point.