Patent ID: 7573693
Filing Date: 2009-08-11
Classification: H01H,H02H

Abstract:
1. A safety switching device for failsafe shutdown of an electric load in response to an input-side switching signal provided from a safety transmitter, the safety switching device comprising: a signal processing part for receiving and evaluating the input-side switching signal from the safety transmitter, at least one switching element adapted to provide an output-side switching signal for shutting down the load, the at least one switching element being controlled by the signal processing part in response to the input-side switching signal, and at least one anti-surge element for canceling voltage spikes when the load is shut down, wherein the anti-surge element has at least a first and a second anti-surge operating mode configured to be activated as an alternative to one another, wherein the anti-surge element has a low response threshold in the first anti-surge operating mode and a high response threshold in the second anti-surge operating mode, and wherein the anti-surge element is switched over from the first to the second anti-surge operating mode if the signal processing part triggers a safety shutdown by appropriately controlling the at least one switching element.