-
公开(公告)号：US3621143A
公开(公告)日：1971-11-16
申请号：US3621143D
申请日：1969-04-04
申请人： LORAIN PROD CORP
CPC分类号： H04M19/006
摘要： A voltage booster circuit for telephone systems utilizing reverse battery supervision. First and second switches control the connection of respective auxiliary sources in series between a central office battery and a subscriber circuit. The conduction of said switches are controlled in accordance with the polarity with which the central office battery is connected to the subscriber circuit to connect between the central office battery and the subscriber circuit that auxiliary source which is in power-aiding relationship to the central office battery. The conduction period of one of the switches is made to predominate over the conduction period of the other during dialing and ringing so as to facilitate the transmission of dial pulses and the generation of a DC boost for energizing a trip relay during ringing.
搜索结果
1 条记录 (耗时 0.009 秒)
筛选
AND
AND
过滤
NOT
NOT