| 摘要 |
PURPOSE:To improve the reliability of the system by detecting the state that a characteristic of a normal state transits to a faulty state and switching the system to the redundancy system after the normal system and the redundancy system are operated in parallel according to the result of detection to prevent intermission of data transmission due to a faulty relay amplifier. CONSTITUTION:Power is applied to the 1st and 2nd amplifiers 11, 12 of a relay amplifier section of a broadcast band network system via switches 13, 14 to drive the amplifiers 11, 12. The amplifiers 11, 12 are inserted in parallel with a transmission line 15 via a signal distributor 16 and a signal synthesizer 17. The switches 13, 14 are controlled by a changeover controller 19 and a faulty current detector 18 is provided between the amplifier 11 and the switch 13 of the normal system. Then the state that the characteristic of the amplifier 11 of the normal system transits to a faulty state is detected by the detector 18 and according to the result of detection, after the amplifier 11 and the amplifier 12 of the redundancy system are driven in parallel, the amplifier is switched to the amplifier 12 of the redundancy system to prevent intermission of data transmission due to the faulty amplifier 11. |
