同线电话自动转换器是供同一条线路连接几部话机的用户之间互相保密之用的。它能够在任何一个话机先摘机通话时,自动切断其它分机。以往的电话自动转换器存在不易克服的三大弊病:(1)不能完全抑制同线它机的拨号串音干扰,或者将振铃信号过分衰减而阻断;(2)使本机的拨号脉冲变窄,出现拨“错号”现象;(3)先用方摘机拨号时,如恰遇后用方也摘 The same line telephone autochanger is used for mutual confidentiality between users who connect several telephone sets on the same line. It can cut off other extensions automatically when any phone is off-hook. In the past, there were three major drawbacks that were not easily overcome by the automatic telephone converter: (1) the dialing crosstalk of the same line with the same line could not be completely suppressed, or the ringing signal was attenuated excessively and blocked; (2) Narrowing, there dialing “wrong number” phenomenon; (3) the first party to dial the machine, such as after the coincidence with the party also pick