Patent ID: 8000070

Claim:
Control circuit for an electric consumer with an inductive load portion, to be connected to a feed voltage source the control circuit comprising: a power driving assembly to connect the consumer electrically in controlled manner to the feed voltage source or to disconnect it therefrom; a free-wheeling assembly to avoid an electric voltage peak occurring when the consumer is electrically disconnected from the feed voltage source; a reverse-connection protected assembly, which avoids a short circuit current between the poles of the feed voltage source when the feed voltage source is connected to the control circuit with reversed polarity, with the power driving assembly being switched in series with a parallel switching part in which the electric consumer forms a first branch and a second branch contains a series circuit of the free-wheeling assembly and the reverse-connection protected assembly; and a diagnostic device connected to two outputs of the control circuit with the two outputs including a first output that is an output of the free-wheeling assembly and a second output that is an output of the power driving assembly, and with at least one of the assemblies being impinged with a control signal at a first input, in order to provide at least one of the control circuit outputs an output signal, which is to be supplied to the diagnostic device to determine failures in the control circuit, the diagnostic device being operative to perform a comparison between the output signal provided at the first output and a threshold value, to determine failures in the control circuit and by comparing the output signal and the threshold value, to establish whether and which assembly has a defect or defective driving, while the control circuit sets different operating statuses in succession in that control signals are assigned to the inputs of the assemblies in succession in order to provide at least one output of the assemblies an output signal, which is to be supplied to the diagnostic device.