| 摘要 |
PURPOSE:To obtain a multivibrator strong against pulse noise, by connecting both ends of a capacitor included in a time constant circuit to each base of a transistor pair constituting a current source circuit. CONSTITUTION:Transistors (TRs)T4, T5 constituting a current source circuit are normally operated, a bias voltage is supplied to a TRT3 via a resistor R3 to turn on the TRT3 and to turn off the TRT2. When a trigger pulse is inputted to an input terminal 1, since the TRT1 turns on, the TRT3 turns off, and the TRT2 turns on, the potential at a connecting point P1 is about zero volt. A charging current flows to a capacitor C via a resistor R0, and when the potential at a connecting point P2 is increased, the TRT4 and the TRT3 turn on, and the TRT2 turns off, the capacitor C is discharged, the potential of the connecting points P1, P2 is equal to the potential of the power supply voltage and a monostable multivibrator is made stable. Since the potential at the points P1, P2 is varied according to the potential of the power supply voltage, no potential difference is caused between the points P1 and P2 at stable state and no malfunction is caused even with pulse noise mixed to the power supply. |
