GB971265A - A subscriber's telephone set - Google Patents
A subscriber's telephone setInfo
- Publication number
- GB971265A GB971265A GB3537461A GB3537461A GB971265A GB 971265 A GB971265 A GB 971265A GB 3537461 A GB3537461 A GB 3537461A GB 3537461 A GB3537461 A GB 3537461A GB 971265 A GB971265 A GB 971265A
- Authority
- GB
- United Kingdom
- Prior art keywords
- resistor
- linear
- impedance
- line
- substation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/738—Interface circuits for coupling substations to external telephone lines
- H04M1/76—Compensating for differences in line impedance
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
971,265. Substation circuits. TELEFONAKTIEBOLAGET L. M. ERICSSON. Sept. 29, 1961 [Oct. 7, 1960; Aug. 10, 1961], No. 35374/61. Heading H4K. To compensate for the variations in line length which may be encountered by a substation a secondary winding N4 on the speech coil N1, N2, N3, is shunted by a non-linear impedance A controlled by a resistor D, the voltage across which depends on the current received from the exchange. If the line connected to terminals La, Lb is short the voltage across resistor D reduces the impedance of A to increase the impedance of the coils N1, N2, N3. If the line is long the impedance of A disconnects winding N4. Two impedances A and two resistors D may be arranged symmetrically in a bridge to provide equal attenuation for both half-cycles of speech and to obtain regulation independent of line polarity. The impedance A may be two oppositely poled rectifiers connected in parallel. The resistor D may be linear or exponentially non-linear as-when comprised by a tungsten filament lamp shunted with a linear resistor. The substation otherwise includes a balance network with resistor RB, capacitors C and CB, and an optional non-linear resistor LS. Protection from acoustic shock originating in the receiver R is provided by non-linear device CS.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE958560 | 1960-10-07 | ||
| SE812461 | 1961-08-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB971265A true GB971265A (en) | 1964-09-30 |
Family
ID=26654820
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB3537461A Expired GB971265A (en) | 1960-10-07 | 1961-09-29 | A subscriber's telephone set |
Country Status (5)
| Country | Link |
|---|---|
| BE (1) | BE608939A (en) |
| DE (1) | DE1204273B (en) |
| FI (1) | FI40640B (en) |
| GB (1) | GB971265A (en) |
| NL (1) | NL269902A (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL168862B (en) * | 1951-04-18 | Dynamit Nobel Ag | METHOD FOR BONDING MATERIALS, SUCH AS PAPER, LEATHER, WOOD AND PLASTICS, USING A POLYESTER-BASED MELTING ADHESIVE. | |
| BE510952A (en) * | 1957-05-10 |
-
0
- NL NL269902D patent/NL269902A/xx unknown
-
1961
- 1961-09-19 FI FI163861A patent/FI40640B/fi active
- 1961-09-29 GB GB3537461A patent/GB971265A/en not_active Expired
- 1961-10-06 BE BE608939A patent/BE608939A/en unknown
- 1961-10-06 DE DET20910A patent/DE1204273B/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FI40640B (en) | 1968-12-31 |
| DE1204273B (en) | 1965-11-04 |
| NL269902A (en) | |
| BE608939A (en) | 1962-02-01 |
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