| 摘要 |
PURPOSE:To attain the coincidence between the operation of an alarm circuit and the result of decision in operation by providing an alarm sending section sending an alarm when an output of a period decision section is consecutive for a predetermined time or over. CONSTITUTION:The titled circuit consists of an amplitude separation section 3 separating an input signal into parts where the amplitude of the input signal whose period (t) changes is a prescribed value and over or below, a period decision section 4 sending an output when the period of the two outputs from the amplitude separation section 3 is shorter than a period T1, and an alarm sending section 2 sending an alarm when the output of the period decision section 4 is consecutive for a predetermined time T2 or over. After the amplitude of the inputted control signal having the period (t) is separated into a part higher than a prescribed value V and a part lower than the value V by two photocouplers 31, 32, the result is fed respectively to corresponding monostable multivibrators (the time constant of them is both a value T1, larger than the time (t)) 41, 42, they are both operated and an alarm is sent when the control signal is consecutive for the time T2 or over. Thus, the operation of the alarm circuit and the decision in the operation are made coincident. |
