Abstract: A sensor device determines an alternating voltage between a conductor and a reference potential, particularly of a switch point drive. In order to reduce the installation cost and effort required to verify the absence of reaction, the sensor device has a sensor element, which is configured for capacitive coupling to the conductor, and a resistance element, which is provided for connection to the reference potential and is connected in series together with the sensor element. The sensor device further has a processing device, which is configured to determine a voltage drop via the resistance element.

Abstract: A diagnostic system for a level-crossing safeguarding system. The safeguarding system has a relay circuit with electrical connection cables that are at least partly guided in a cable conduit. The cable conduit has a longitudinal access side with a detachable cover. The diagnostic system is simplified in that the cover is configured for receiving a plurality of current sensors of the diagnostic system and the plurality of current sensors are disposed, in particular fastened, next to one another in the cover in the longitudinal direction of the cover. There is also described a current sensor for such a diagnostic system and to a method for installing such a diagnostic system.

Abstract: A sensor device determines an alternating voltage between a conductor and a reference potential, particularly of a switch point drive. In order to reduce the installation cost and effort required to verify the absence of reaction, the sensor device has a sensor element, which is configured for capacitive coupling to the conductor, and a resistance element, which is provided for connection to the reference potential and is connected in series together with the sensor element. The sensor device further has a processing device, which is configured to determine a voltage drop via the resistance element.

Abstract: A signal transmitter contains at least one first luminous element, at least one second luminous element and an interface for connecting the signal transmitter to a signal box. A drive device is connected between the interface and the at least two luminous elements and the drive device is configured in such a way that, in the case of a switch-on signal coming from the signal box for the second luminous element, the drive device controls the activation of the luminous element depending on the signaling state of the first luminous element.

Abstract: A key lock which can be used particularly flexibly and cost-effectively has a communication device for wire-free linking of the key lock to an actuating mechanism. The key lock further has a cable-independent power supply device for autonomously providing the electrical power required for extended operation of the key lock.

Abstract: A signal transmitter contains at least one first luminous element, at least one second luminous element and an interface for connecting the signal transmitter to a signal box. A drive device is connected between the interface and the at least two luminous elements and the drive device is configured in such a way that, in the case of a switch-on signal coming from the signal box for the second luminous element, the drive device controls the activation of the luminous element depending on the signaling state of the first luminous element.

Abstract: A key lock which can be used particularly flexibly and cost-effectively has a communication device for wire-free linking of the key lock to an actuating mechanism. The key lock further has a cable-independent power supply device for autonomously providing the electrical power required for extended operation of the key lock.