| 摘要 |
<p>PURPOSE:To vary easily the time constant of a monostable multivibrator by using an integrating circuit consisting of an operational amplifier and a level comparator and comparing the integral voltage having a linear gradient with a prescribed reference voltage. CONSTITUTION:Since an output voltage E0 of an operational amplifier 210 rises with a certain gradient until an FET 214 is turned on, this voltage E0 becomes a level proportional to the length of the period of an input pulse Pf. When E0>thetaV is true between the voltage E0 and a reference voltage thetaV, an output MQ of an operational amplifier 220 becomes low-level. Consequently, since the time constant of a monostable multivibrator 20 is determined by the gradient of the output voltage E0 of an integrating circuit 21 and the comparison reference voltage thetaV of a comparing circuit 22, the period of the monostable multivibrator 20 is changed when a variable resistance 221 is varied.</p> |
