Abstract:
A safety circuit arrangement for failsafe connection or disconnection of a hazardous installation has a control device, which is designed to connect or interrupt, in failsafe fashion, a power supply path to the installation. The safety circuit arrangement also has a signaling device, which is connected to the control device via a two-wire line having a first core and a second core. The signaling device has an actuator, which can change between a defined first state and a second state. Between the two cores is a substantially constant voltage when the actuator is in the second state. A pulse generator in the signaling device causes a voltage dip between the first core and the second core in order to generate a defined pulsed signal comprising a plurality of signal pulses on the lines, when the actuator is in the defined first state.
Abstract:
A safety switching device for fail-safely disconnecting an electrical load has an input part for receiving a safety-relevant input signal, a logic part for processing the at least one safety-relevant input signal, and an output part. The output part has a relay coil and four relay contacts. The first and second relay contacts are arranged electrically in series with one another. The third and fourth relay contacts are also arranged electrically in series with one another. The first and the third relay contacts are mechanically coupled to each other and form a first group of positively driven relay contacts. The second and the fourth relay contacts are mechanically coupled to each other and form a second group of positively driven relay contacts. The logic part redundantly controls the first and the second groups of positively driven relay contacts to selectively allow, or to interrupt in a fail-safe manner, a current flow to the electrical load, depending on the safety-relevant input signal. The relay coil is electromagnetically coupled to the first and second groups of positively driven relay contacts so that the logic part can control the relay contacts together via a single relay coil.
Abstract:
A safety switching device for controlling a load having at least one input for receiving an input signal and one output for outputting an output signal, and having an electrical circuit which provides the output signal as a function of the input signal. The electrical circuit is arranged on a printed circuit board and is coupled to at least one setting component for setting an operating parameter of the safety switching device. The surface of the printed circuit board defines a mounting plane, and the at least one setting component has an adjusting element in a housing and is arranged recessed on the printed circuit board so that the housing of the adjusting element intersects the mounting plane.
Abstract:
A safety circuit for fail-safe shutdown of a dangerous technical system with a plurality of disconnectable system component groups comprises a plurality of safety switching devices electrically connected to one another in series to form a closed-loop monitoring circuit in which electric monitoring current flows through the safety switching devices. Each of the safety switching devices includes: a fail-safe control unit that detects and evaluates information about a current operating state of any system component group assigned to it; and a current flow adjuster that changes the current flow within the monitoring circuit to interrupt the monitoring circuit in response to detection of a safety command by the safety switching device. The fail-safe control units generate a shutdown signal in response to an interruption of the current flow within the monitoring circuit, which causes the fail-safe shutdown of any of the system component group not already shut down.
Abstract:
An emergency off-switch for triggering an emergency switch-off function has an actuator and two electrical contact points that can be disconnected from one another by the actuator. The emergency off-switch has an active operating state in which the emergency switch-off function can be triggered by moving the actuator, and a passive operating state in which the emergency off-switch is functionless. The emergency off-switch further has a visualization unit having at least a first and a second display state. The emergency off-switch is visually highlighted in the first display state, and the emergency off-switch is neutrally represented in the second display state. The visualization unit adopts the first display state in the active operating state and adopts the second display state in the passive operating state. The emergency off-switch also has a monitoring unit which monitors whether the visualization unit is in the first or in the second display state.