PL41742B1
(cs )
1958-12-15
CA1138138A
(en )
1982-12-21
Line circuit
US2962554A
(en )
1960-11-29
Current-feed arrangement in automatic telephone and telegraph systems
US3627952A
(en )
1971-12-14
Direct current reduction network for amplification telephone sets
US4112262A
(en )
1978-09-05
Telephone station repeater
JPH0241228B2
(cs )
1990-09-17
US3816917A
(en )
1974-06-18
Telephone conference amplifier
US3941941A
(en )
1976-03-02
Relayless switching circuit for application of ringing signals
US3270142A
(en )
1966-08-30
Variable impedance electrical circuits
CA1071341A
(en )
1980-02-05
Automatic group exclusion circuit for a key telephone system
JPS5986951A
(ja )
1984-05-19
電話設備
US3299215A
(en )
1967-01-17
Bipolar transistor amplifier for telephone set use
US6134323A
(en )
2000-10-17
Telecommunications system, an automatic branch exchange, a line card, a supply circuit for a telecommunications line, and a telecommunications subscriber device
CA1074034A
(en )
1980-03-18
Telephone line circuit with differential loop current sensing and compensation
JPH0741234Y2
(ja )
1995-09-20
電話機用ドアホン接続回路
US3440356A
(en )
1969-04-22
Automatically compensating telephone substation
JPS55154866A
(en )
1980-12-02
Current supply circuit for telephone switchboard
JPS58215849A
(ja )
1983-12-15
ル−プ状態検出回路
PL143443B1
(en )
1988-02-29
Electronic subscriber line unit
PL160626B1
(pl )
1993-04-30
Uklad wyposazenia centralowego aparatu centralnej baterii C B PL PL PL
SU500572A1
(ru )
1976-01-25
Усилитель мощности
JPS61220556A
(ja )
1986-09-30
電話交換機の通話電流供給回路
JPS6317389B2
(cs )
1988-04-13
JPS61199397A
(ja )
1986-09-03
通話路用ル−プ回路
JPS63301657A
(ja )
1988-12-08
呼出信号発生回路