Patent ID: 7813097

Claim:
An error detection apparatus for detecting an error in a power signal output by an external device switchable by a switching signal, comprising: a comparing unit adapted for comparing the power signal or a signal derived from the power signal with a reference signal in order to yield a comparison signal; a switching unit adapted for providing the switching signal to the external device dependent on a control signal, the switching unit being designed to disregard the control signal and to ensure that the external device is switched off upon provision of a triggering signal to the switching unit; a triggering unit adapted for providing the triggering signal to the switching unit depending on the control signal and the comparison signal, or depending on the switching signal and the comparison signal; wherein the switching unit comprises: a protection unit adapted to provide a fault signal that is distinct from the control signal and where the fault signal is maintained upon the switching unit receiving the triggering signal until a reset signal is received, and a driving unit adapted to provide the switching signal depending on the control signal unless the driving unit is supplied with the fault signal; and a surveillance unit adapted for surveying the power signal or the signal derived from the power signal as to whether the power signal assumes an undesired state and for influencing the control signal upon an occurrence of the undesired state.