A circuit arrangement for switching an electrical load comprising an electrical switching element with a control input and an output; a control unit connected to the control input to drive the electrical switching element, in a first switching state, to generate a first output signal forming a switch-on signal for the load and, in a second switching state, to generate a second output signal, smaller than the first output signal, forming a switch-off signal for the electrical load; a safety output connected electrically to the electrical switching element output and to which the electrical load is connected; a decoupling apparatus arranged between the electrical switching element output and the safety output; a first output signal detecting apparatus connected to the electrical switching element output; and a second output signal detecting apparatus arranged in a circuit path between the decoupling apparatus and the safety output.

The invention relates to a safety switching device (10) comprising a control side (40) with at least one single-error tolerance, having a first and second control unit (12, 14), each formed on an actuation side (50) for emitting a switch command (20) to at least two switching elements (52, 54, 56), and comprising a monitoring unit (30, 30.1, 30.2, 30.3) having a first and a second connection element (31, 36), and which monitoring unit (30, 30.1, 30.2, 30.3) is designed to emit the switch command (20) to at least one switching element (52, 54, 56) of a load circuit (23), characterised in that the at least two switching elements (52, 54, 56) are each designed as standard components that are free from a forced guidance of the contacts (62) thereof, and the first connection element (31) is directly connected to the second control unit (14) via a first feedback channel (42) and the second connection element (36) is directly connected to the first control unit (12) via a second feedback channel (44).

A series connection having multiple safety switches. Here, the series connection includes wiring connecting the safety switches. The safety switches can output signals. Depending on the registration of these signals by additional safety switches of the series connection it will be detected whether the wiring is laid out for connecting a master, and whether such a master is connected. Depending on this, the operation of the safety switches is predetermined.

The invention relates to a safety switching device (10) comprising a control side (40) with at least one single-error tolerance, having a first and second control unit (12, 14), each formed on an actuation side (50) for emitting a switch command (20) to at least two switching elements (52, 54, 56), and comprising a monitoring unit (30, 30.1, 30.2, 30.3) having a first and a second connection element (31, 36), and which monitoring unit (30, 30.1, 30.2, 30.3) is designed to emit the switch command (20) to at least one switching element (52, 54, 56) of a load circuit (23), characterised in that the at least two switching elements (52, 54, 56) are each designed as standard components that are free from a forced guidance of the contacts (62) thereof, and the first connection element (31) is directly connected to the second control unit (14) via a first feedback channel (42) and the second connection element (36) is directly connected to the first control unit (12) via a second feedback channel (44).

A circuit arrangement for switching an electrical load comprising an electrical switching element with a control input and an output; a control unit connected to the control input to drive the electrical switching element, in a first switching state, to generate a first output signal forming a switch-on signal for the load and, in a second switching state, to generate a second output signal, smaller than the first output signal, forming a switch-off signal for the electrical load; a safety output connected electrically to the electrical switching element output and to which the electrical load is connected; a decoupling apparatus arranged between the electrical switching element output and the safety output; a first output signal detecting apparatus connected to the electrical switching element output; and a second output signal detecting apparatus arranged in a circuit path between the decoupling apparatus and the safety output.

A series connection having multiple safety switches. Here, the series connection includes wiring connecting the safety switches. The safety switches can output signals. Depending on the registration of these signals by additional safety switches of the series connection it will be detected whether the wiring is laid out for connecting a master, and whether such a master is connected. Depending on this, the operation of the safety switches is predetermined.