| 摘要 |
<p>A loop sensing circuit (18, 20, 22, 24, 54, 56) is coupled between a solid state hybrid circuit (10) that provides signal conversion between a pair of unidirectional transmission paths (RX, TX) and a bidirectional subscriber loop (T, R). The loop sensing circuit includes placing respective protection resistors (20, 22) coupled in parallel with first and second sensing resistors (18, 24) between the hybrid and the subscriber loop terminals to provide a dc current path between the bidirectional subscriber loop and the hybrid circuit. </p> |
