Abstract: A signaling device for a safety circuit has an input part for receiving an external state variable, at least one switching element and a control part. The control part controls the at least one switching element as a function of the external state variable, such that a signal applied to the input is communicated to the output. According to one aspect of the invention, the input of the switching element is internally connected to a fixed potential, preferably a fixed High potential. In a safety circuit for turning off a hazardous installation, such signaling devices are connected in series with one another to a safety controller. In such an arrangement, the control part of the downstream second signaling device also controls its switching elements as a function of the output of the first signaling device.

Abstract: A safety switch, which is particularly intended for monitoring a guard door on an automated installation, has an actuator and a sensor. The actuator comprises an actuator antenna and the sensor comprises a sensor antenna. The actuator and the sensor are coupled to one another like a transformer, in particular like a transponder, when the guard door is in the closed position. According to one aspect of the invention, the sensor antenna has a magnetic directional characteristic which allows transformer coupling with the actuator in at least two mutually perpendicular spatial directions as seen from the sensor antenna.

Abstract: A signaling device for a safety circuit has an input part for receiving an external state variable, at least one switching element and a control part. The control part controls the at least one switching element as a function of the external state variable, such that a signal applied to the input is communicated to the output. According to one aspect of the invention, the input of the switching element is internally connected to a fixed potential, preferably a fixed High potential. In a safety circuit for turning off a hazardous installation, such signaling devices are connected in series with one another to a safety controller. In such an arrangement, the control part of the downstream second signaling device also controls its switching elements as a function of the output of the first signaling device.

Abstract: A safety switching module for safely switching-off an electrical load (43), comprising a first and a second switching control device (20A, 20B); a first and a second switching element (24.1, 24.2) both being series-connected with each other and forming a first current path (26.1) for supplying the load, whereby the first switching element (24.1) can be controlled by the first switching control device (20A) and the second switching element (24.2) can be controlled by the second switching control device (20B); and an evaluation and control device (12) for testing the switching-off ability of at least one switching element. A third and a fourth switching element (24.3, 24.4) are provided which are connected to each other in series, are connected in parallel to the series connection consisting of the first and second switching elements (24.1, 24.2) and form a second current path (26.2), the third switching element (24.

Abstract: A safety switch, which is particularly intended for monitoring a guard door on an automated installation, has an actuator and a sensor. The actuator comprises an actuator antenna and the sensor comprises a sensor antenna. The actuator and the sensor are coupled to one another like a transformer, in particular like a transponder, when the guard door is in the closed position. According to one aspect of the invention, the sensor antenna has a magnetic directional characteristic which allows transformer coupling with the actuator in at least two mutually perpendicular spatial directions as seen from the sensor antenna.

Abstract: A safety switching module for safely switching-off an electrical load (43), comprising a first and a second switching control device (20A, 20B); a first and a second switching element (24.1, 24.2) both being series-connected with each other and forming a first current path (26.1) for supplying the load, whereby the first switching element (24.1) can be controlled by the first switching control device (20A) and the second switching element (24.2) can be controlled by the second switching control device (20B); and an evaluation and control device (12) for testing the switching-off ability of at least one switching element. A third and a fourth switching element (24.3, 24.4) are provided which are connected to each other in series, are connected in parallel to the series connection consisting of the first and second switching elements (24.1, 24.2) and form a second current path (26.2), the third switching element (24.