Break detection device

A break detection device comprising:

• a sensor of which an output signal varies when vibration occurs in a rope of an elevator;
• and
• processing circuitry configured
• to extract, from the output signal from the sensor, a vibration component in a specific frequency band;
• to attenuate, from the extracted vibration component using low-pass filters, a steady vibration component and a progressively increasing vibration component to extract a determination signal;
• to detect, on the basis of the extracted determination signal, occurrence of an abnormal variation in the output signal from the sensor;
• and
• to determine, when the occurrence of the abnormal variation is detected, whether or not the rope has a broken portion on the basis of a position of a car of the elevator at an occurrence time of the abnormal variation, wherein
• a section in which the car moves is imaginarily divided into a plurality of vertically consecutive unit sections, and
• the determination signal is extracted so as to correspond to each of the unit sections with each of the low-pass filters corresponding to a different one of the unit sections.