NL70720C - - Google Patents
Info
- Publication number
- NL70720C NL70720C NL70720DA NL70720C NL 70720 C NL70720 C NL 70720C NL 70720D A NL70720D A NL 70720DA NL 70720 C NL70720 C NL 70720C
- Authority
- NL
- Netherlands
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
- H04Q1/446—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency
- H04Q1/4465—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency the same frequency being used for all signalling information, e.g. A.C. nr.9 system
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interface Circuits In Exchanges (AREA)
- Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
- Amplifiers (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB11782/41A GB551951A (en) | 1941-09-15 | 1941-09-15 | Improvements in or relating to electric signalling systems |
Publications (1)
Publication Number | Publication Date |
---|---|
NL70720C true NL70720C (es) |
Family
ID=27799776
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NL70720D NL70720C (es) | 1941-09-15 |
Country Status (6)
Country | Link |
---|---|
US (1) | US2343759A (es) |
BE (1) | BE479786A (es) |
CH (1) | CH254957A (es) |
FR (1) | FR933246A (es) |
GB (1) | GB551951A (es) |
NL (1) | NL70720C (es) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2476311A (en) * | 1943-02-01 | 1949-07-19 | Sperry Corp | Ultra high frequency discriminator and apparatus |
US2533286A (en) * | 1946-07-22 | 1950-12-12 | Univ Minnesota | Heat sensitive circuits |
BE481448A (es) * | 1947-02-07 | |||
US2706272A (en) * | 1949-11-03 | 1955-04-12 | Jones Lloyd | Voltage stabilizing circuit |
US2801290A (en) * | 1951-09-17 | 1957-07-30 | Telefunken Gmbh | Calling signal responder arrangements |
US2957950A (en) * | 1954-11-18 | 1960-10-25 | Bell Telephone Labor Inc | Transistor selective ringing circuit |
US2987713A (en) * | 1957-07-12 | 1961-06-06 | Kidde & Co Walter | Sensitivity control of apparatus for detecting distrubances in an enclosure |
-
0
- BE BE479786D patent/BE479786A/xx unknown
- NL NL70720D patent/NL70720C/xx active
-
1941
- 1941-09-15 GB GB11782/41A patent/GB551951A/en not_active Expired
-
1942
- 1942-06-17 US US447394A patent/US2343759A/en not_active Expired - Lifetime
-
1946
- 1946-05-24 CH CH254957D patent/CH254957A/de unknown
- 1946-09-04 FR FR933246D patent/FR933246A/fr not_active Expired
Also Published As
Publication number | Publication date |
---|---|
GB551951A (en) | 1943-03-17 |
BE479786A (es) | |
FR933246A (fr) | 1948-04-14 |
CH254957A (de) | 1948-05-31 |
US2343759A (en) | 1944-03-07 |