US3731234A
(en )
1973-05-01
Combined voice frequency transmission and dc signaling circuit
FR2848721A1
(fr )
2004-06-18
Transformateur a changement de mode selectif en frequences
US5274704A
(en )
1993-12-28
Transformer telephone line interface circuit
CA1088687A
(en )
1980-10-28
Automatic signal level adjusting circuits for use in telephone sets
KR100821422B1
(ko )
2008-04-10
평형 전송 종단 장치 및 그것을 이용한 수신 장치
BE437316A
(sr )
US3582563A
(en )
1971-06-01
Apparatus for matching the impedance of a telephone set to a line
US5038375A
(en )
1991-08-06
Circuit arrangement for preventing gain from responding to frequency variation despite the presence of an isolation transformer
CA1157978A
(en )
1983-11-29
Loop sensing circuit for use with a subscriber loop interface circuit
US3810247A
(en )
1974-05-07
Telephone set circuit
US2286069A
(en )
1942-06-09
Telephone set circuit
CA1267738A
(en )
1990-04-10
Telephone set comprising a line voltage stabilizer having a dc supply point
JP3607639B2
(ja )
2005-01-05
２線４線変換回路
JPS6042946A
(ja )
1985-03-07
適応線路ハイブリツド回路
US1811947A
(en )
1931-06-30
Noise suppressing circuit
US2775649A
(en )
1956-12-25
Telephone subscriber sets
KR100277090B1
(ko )
2001-01-15
전류 제한 가입자 인터페이스 회로
CH290147A
(fr )
1953-04-15
Poste téléphonique d'abonné.
US1654633A
(en )
1928-01-03
Recording system
JPH03289221A
(ja )
1991-12-19
擬似通信回路網
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(en )
2006-06-27
Integrated line inductor and line feed resistor
US4580187A
(en )
1986-04-01
A-C current limiting device
US2318681A
(en )
1943-05-11
Telephone set
GB2075798A
(en )
1981-11-18
Central office interface circuit
US4899379A
(en )
1990-02-06
Circuit arrangement for the connection of line circuits of a digital time multiplex-telephone network