| 摘要 |
PURPOSE:To output the signal showing failure of a counter or comparator, by comparing the input pulse with the output from the comparator at a coincidence circuit. CONSTITUTION:If a comparator C malfunctions that L level is outputted regardless that the content of the counters A, B is in agreement, at normal operation, the relation that the input pulse applied to a coincidence circuit 2 and the output signal E from the comparator C are completely in uncoincidence is changed into coincidence, and the signal of H level is outputted from the coincidence circuit 2. Monostable multivibrators M1, M2 are at L level for a very short time of leading and trailing of the input pulse P, and they are usually at H level, allowing to output failure signal of H level from the AND circuit 3 by keeping the output signal from the coincidence circuit 2 as it is. Further, the similar operation can be obtained when there is a counter mistake in the counters A, B. |
