| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect the disturbance of period of an input periodic signal with a simple structure. SOLUTION: A monostable multivibrator (monomulti) 10 outputs monostable mode with the leading edge and trailing edge of an input periodic signal S1 as trigger. This monostable mode is set shorter than one normal period of the signal S1, and when the period of the signal S1 is shorter than the normal one, the monostable mode outputted by the monomulti 10 is continued. Since a monomulti 20 uses the leading edge and trailing edge of the monostable mode in the output signal S10 of the monomulti 10 as trigger, no trigger is added to the monomulti 20 when the monomulti 10 continues the monostable mode, and the monomulti 20 escapes from the monostable mode and shows an abnormality in a disturbance detection signal S20. When the period of the signal S1 is disturbed in the direction of extending the period, the output signal S10 continues the state escaping from the monostable mode, no trigger is added to the monomulti 20, and the signal S20 shows an abnormality.</p> |
