| 摘要 |
PURPOSE:To prevent a bistable multivibrator from causing swinging through amplification by frequencies. CONSTITUTION:Terminals 1 and 2 are connected to telephone main wires, filters 3 and 11, 13 and 24, and 25 and 35 are equal in kind respectively, and signals having passed through respective filters are amplified by passing through corresponding amolifiers 10 and 9, 22 and 21, and 33 and 34. Then, when a rectified signal from amplifier 14 is greater than that from amplifier 15, photocoupler 12 operates to send a signal from terminal 1 to terminal 2 by way of filter 13, amplifier 22 and filter 24, but a signal from terminal 2 is not sent to terminal through the operations of diode switches 7, 18 and 32. |
