| 摘要 |
This disclosure describes a telephone subscriber loop range extender having a signaling mode and a transmission mode. In the former, a resistive shunt is applied across the loop with each dial pulse to aid operation of the pulsing relay for an originating cell. For a terminating call, the shunt is applied upon answer, either during ringing or during the silent interval, to aid operation of the ring-trip relay. In the transmission mode, voice frequency gain and greater transmitter voltage are applied to the loop. A control circuit consisting of logic, timing and relay driving circuits, acts upon loop voltage and current data to control shunt action and mode selection.
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