| 摘要 |
PURPOSE:To attain the signal amplification in a semidouble communication mode without using any special control signal line, control data, etc., by inhibiting the output of an amplifier which is opposite in the direction, if a carrier signal at one side is detected. CONSTITUTION:A carrier signal sent from a communication medium 5b is amplified by an amplifier C13 and supplied to a carrier detecting part b15. Then a carrier-detected output signal 21 is outputted through the part b15. The output of an amplifier D14 is permitted by the signal 21 and at the same time the output of an amplifier A10 is inhibited. As a result, the carrier signal if outputted later from a communication medium 5a is not sent to a stage further than the amplifier A10 of a repeater 3, and therefore not to the side of the medium 5b. The same way of control is executed even in an adverse case. |
