GB2173071B
(en )
1988-09-07
Telephone answering system with paging function
EP0275193A3
(en )
1990-10-24
Telephone having receive call indicating function and mute/light key
GB2158677B
(en )
1988-02-03
Line powered flasher circuit for providing visual indication of telephone ringing signal
IT1176152B
(en )
1987-08-18
TELEPHONE CALL SIGNAL GENERATOR
GB8718068D0
(en )
1987-09-03
Telephone paging system
GB2169775B
(en )
1988-12-21
Ringing signal sending-out circuit
EP0394491A4
(en )
1992-12-09
Voice signal demodulation circuit
PL276253A2
(en )
1989-09-18
Two-wire circuit of loud-speaking paging system with call signal generation
GB2113044B
(en )
1985-05-01
Telephone ringing signal generation
EP0363626A3
(en )
1990-07-11
Digital signal level conversion circuit arrangement
EP0394490A4
(en )
1991-04-03
Voice signal demodulation circuit
GB8606151D0
(en )
1986-04-16
Telephone system circuit
GB2209907B
(en )
1991-05-29
Telephone ringing circuit
GB2250661B
(en )
1994-09-21
Circuit for transmitting voice signals and dial pulses
KR880010911U
(en )
1988-07-28
Call holding signal generating circuit of telephone
KR890015123U
(en )
1989-08-11
Strobe signal generation circuit of DTMF transmitter and receiver
GB8805916D0
(en )
1988-04-13
Phone alarm
KR880022865U
(en )
1988-12-27
Ring signal generation circuit of telephone
PL269525A1
(en )
1989-06-26
System of an electronic telephone set
GB8803209D0
(en )
1988-03-09
Telephone intruder alarm system
GB8803208D0
(en )
1988-03-09
Telephone intruder alarm receiver
CS331888A1
(en )
1989-07-12
Connection of electronic telephone set
CS423288A1
(en )
1989-09-12
Connection of electronic telephone set
CS871288A2
(en )
1990-08-14
Connection of electronic telephone set
CS254988A1
(en )
1989-03-14
Connection of electronic telephone set