Abnormality monitoring apparatus

An abnormality monitoring apparatus that monitors an energization abnormality of a motor having a motor winding, comprising:

• a drive circuit unit configured to switch an energization to the motor winding;
• a current detection unit configured to detect a motor current, which is a current flowing through the motor winding;
• a current cutoff unit configured to cut off the motor current;
• a first control unit having an energization control unit configured to control energization of the motor winding and an energization state notification unit configured to output an energization state signal according to an energization command state;
• a second control unit provided separately from the first control unit and having an abnormality monitoring unit configured to monitor an abnormality based on the energization state signal so as to perform fail-safe measure according to a monitoring result;
• a signal cutoff unit configured to block on/off command from the first control unit to all drive elements constituting the drive circuit unit by the second control unit, wherein
• the current detection unit detects an energization direction of the motor current, and
• when the second control unit detects an abnormality in rotation direction mismatch where a rotation direction of the motor according to the energization direction of the motor current detected by the current detection unit and a rotation direction of the motor according to the energization state signal do not match, the second control unit turns off the signal cutoff unit by the command thereof so as to cut off the motor current.