公开(公告)号：US4296337A

公开(公告)日：1981-10-20

申请号：US84915

申请日：1979-10-15

申请人： Dale E. Stone

发明人： Dale E. Stone

IPC分类号： H04M19/00 ,  H03K5/24

CPC分类号： H04M19/006

摘要： The disclosure shows a telephone range extender which is automatically adaptable to the length of the connected subscriber loop. A loop resistance detector within the range extender discriminates between loops within a plurality of ranges of lengths. For extremely short loops not requiring range extension, the range extender circuits are disconnected from the loop. For intermediate length loops, the gain of a bidirectional voice frequency amplifier is set at a low value to provide just sufficient gain for these loops. For longer loops, the gain of the amplifier is increased to provide sufficient amplification for the longer range. For extremely long loops, the range extender is disconnected since such loops must be served by remote amplification facilities. An automatic range extender of this type is shown connected behind the first stage of the central office switch in order to concentrate range extenders on a large plurality of subscriber loops.

摘要翻译： 本公开示出了电话范围扩展器，其自动适应所连接的用户环路的长度。 范围扩展器内的环路电阻检测器在多个长度范围内的环路之间进行区分。 对于不需要范围扩展的极短的回路，范围扩展器电路与环路断开连接。 对于中间长度环路，双向语音放大器的增益设置为低值，以便为这些环路提供足够的增益。 对于较长的环路，放大器的增益会增加，以便为更长的范围提供足够的放大。 对于极长的回路，范围扩展器是断开的，因为这样的环路必须由远程放大设备提供。 这种类型的自动量程扩展器被示为连接在中心局交换机的第一级之后，以便将范围扩展器集中在大量多个用户环路上。