| Patents for H04M 5 - Manual exchanges (1,342) |
|---|
| 12/18/1990 | CA1278048C Integrated multisound signal demodulator circuit |
| 08/08/1990 | CN1009148B Monitor for longdistance telephone |
| 02/07/1990 | CN1039514A Exchange system having originating call restriction function |
| 11/08/1989 | CN2047469U Group telephone with exchange capacity and capable of making autside connections |
| 09/26/1989 | CA1261420A1 Pin board matrix |
| 09/12/1989 | US4866775 Intergrated multisound signal demodulator circuit |
| 05/24/1989 | CN1033137A Long distance telephone monitor |
| 05/02/1989 | US4827342 Video signal processing apparatus for removing noise from reproduced signals |
| 04/04/1989 | US4819262 Electronic gating control for manual telephone switchboard |
| 03/08/1989 | EP0110994B1 Am stereo receiver |
| 02/01/1989 | CN2031986U Multi-system type complete set magneto-telephone exchange |
| 11/02/1988 | CN87215128U Electronic numeral display device |
| 10/18/1988 | US4778393 Pin board matrix |
| 10/12/1988 | CN87215223U Automatic all-electronic responder for telephone operators |
| 09/14/1988 | CN87211406U Microcomputer controlled telephone operating picket device |
| 10/28/1987 | CN86204850U Manual dispatchine exchanger for mine |
| 09/09/1987 | EP0235292A1 Pin board matrix. |
| 01/21/1987 | CN86200686U Complex manual telephone exchanger |
| 12/31/1986 | CN85205604U Magneto telephone line concentrator |
| 12/31/1986 | CN85105268A Telephone auto-exchange technology with frequency shared call in the same wire |
| 12/10/1986 | CN86200589U Two-coloured indicating lamp for telephone exchange |
| 12/04/1986 | WO1986007208A1 Pin board matrix |
| 07/02/1986 | CN85201737U Local battery switchoard of transistor ic |
| 01/08/1986 | EP0167387A2 Video signal processing apparatus |
| 11/05/1985 | CA1196387A1 Signal interference protection circuit for am stereo receiver |
| 12/27/1984 | CA1180141A Echo canceller system |
| 12/27/1984 | CA1180140A Electronic tone ringer |
| 12/18/1984 | US4489431 Signal interference protection circuit for AM stereo receiver |
| 09/25/1984 | CA1175171A1 Testing facility for telephone conference bridge |
| 01/03/1984 | CA1159976A1 Low cost user reprogrammable communication system |
| 12/27/1983 | US4423466 Supports for telephone jacks and circuit boards incorporating such supports |
| 12/22/1983 | WO1983004459A1 Signal interference protection circuit for am stereo receiver |
| 05/10/1983 | CA1146289A1 Double talk detector for echo cancellers |
| 10/12/1982 | US4354058 Portable field control unit for emergency telephone communications |
| 07/06/1982 | US4338496 Testing facility for telephone conference bridge |
| 02/23/1982 | CA1118875A1 Identifier for manual switchboards with conference facility |
| 10/13/1981 | US4295007 Line identifier for switchboards |
| 02/24/1981 | US4252998 Identifier for manual switchboards with conference facility |
| 08/28/1979 | US4165949 High efficiency split flow turbine for compressible fluids |
| 02/20/1979 | US4140918 Electrical jack and patch cord assemblies |
| 03/21/1978 | US4080040 Electrical jack and patch cord plug assemblies |
| 05/10/1977 | US4022984 Telephone answering service console |