| 摘要 |
PURPOSE:To simplify a receiving circuit even when the number of feeders is large by adding a code for receiving feeder selection to a carrier signal, and scanning and selecting it by a receiver. CONSTITUTION:A scanning circuit 14 scans feeder current transformers 6a-6c successively at intervals T2 unless a signal arrives. If a signal arrives at the current transformer 6a at a point t1 of time, a signal passed through a filter 9a is detected by a signal level decision circuit 15 at a point t2 of time and a control circuit 16 locks the circuit 14 to the current transformer 6a to receive specific data. When the reception of the is completed, the output of the decision circuit 15 is ceased and the circuit 14 scans the next current transformer 6b under the command of the control signal 16 to hold the next reception in readiness. |
