FAULT DETECTING SYSTEM FOR PULSE ENCODER

摘要

PURPOSE:To detect faults of a pulse encoder by providing two slit trains arranged so as to have 90 deg. phase shift and a slit generating one pulse per rotation on a rotary disc. CONSTITUTION:A rotary disc is provided with A-phase slit train 11 dividing the circumference having radius RA into N, B-phase slit train 12 dividing the circumference having radius RB into N and a Z-phase slit 13 on the circimference having radius Rz. The A- and B-phase slit trains are arranged so as to biased by 1/4 pitch. Thus, faults can be detected by judging the levels of A- and B-phase pulses at leading and trailing edge parts of Z-phase pulse.