| 摘要 |
PURPOSE:To relieve the load of a driver by providing a transmitter transmitting a different frequency to each bus stop, allowing a line bus to receive this transmission signal and broadcasting automatically the name of its bus stop when a receiving level reaches a prescribed value. CONSTITUTION:Bus stops 20...2n-1 of a bus line 1 are provided respectively with transmitters 30...3n-1 using a specific high frequency multiplying or demultiplying a frequency of a signal to be transmitted starting from the bus stop 20 start point. A local oscillator 16 is set by a synthesizer 17 in a receiver 5 in a line bus 4 at first to receive a radio wave transmitted from the bus stop 21. When the bus approaches the bus stop 21 and the receiving level reaches a prescribed value ES, a flip-flop 19 outputs, and a tape reproducer 20 is operated to broadcast automatically the name of the bus stop, the value of a counter 21 is incremented and the synthesizer 17 sets the frequency of a local oscillator 16 to receive the transmission frequency of the next bus stop.
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