GB469067A - Attenuation equalizers for electric transmission and like systems - Google Patents
Attenuation equalizers for electric transmission and like systemsInfo
- Publication number
- GB469067A GB469067A GB33693/36A GB3369336A GB469067A GB 469067 A GB469067 A GB 469067A GB 33693/36 A GB33693/36 A GB 33693/36A GB 3369336 A GB3369336 A GB 3369336A GB 469067 A GB469067 A GB 469067A
- Authority
- GB
- United Kingdom
- Prior art keywords
- network
- characteristic
- variable resistance
- impedance
- resistance
- 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
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/04—Control of transmission; Equalising
- H04B3/14—Control of transmission; Equalising characterised by the equalising network used
- H04B3/143—Control of transmission; Equalising characterised by the equalising network used using amplitude-frequency equalisers
- H04B3/145—Control of transmission; Equalising characterised by the equalising network used using amplitude-frequency equalisers variable equalisers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
- F16K17/02—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side
- F16K17/04—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded
- F16K17/10—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded with auxiliary valve for fluid operation of the main valve
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Networks Using Active Elements (AREA)
- Filters And Equalizers (AREA)
Abstract
469,067. Impedance networks. STANDARD TELEPHONES & CABLES, Ltd. Dec. 8, 1936, No. 33693. Convention date, Jan. 30. [Class 40 (iii)] Attenuation equalizers, particularly suitable for use with transmission lines whose characteristics are subject to variation with temperature and humidity, comprise a network N, Fig. 1, having input terminals 1, 2, output terminals 3, 4, and side terminals 5, 6 to which a variable impedance Z is connected. The arrangement is such that the attenuations represented by the ordinates of the normal characteristic A, Fig. 2, are obtained when Z has a particular value Z0, but are increased so as to yield the characteristic B when Z=0, or decreased to yield the characteristic C when Z=#, while intermediate values of Z yield characteristics such as C, C<1>, and the differences between A and C or C<1> bear to the differences between A and B or B<1> a ratio which either is constant throughout the curves or is a simple function of the frequency. General theory. The invention consists in designing the network N so that Z<2>0 = Z5<SP>2>6. Z2# Z20, where Z0 is a datum value of Z chosen in relation to the network, Z56 is the impedance of the network at terminals 5, 6 and Z2#, Z20 are the values of the transfer impedance E/I2 when Z=# and Z = 0 respectively, E being the input voltage and I2 the output current. Then if e<-#> is the ratio of I2 to a fixed reference current equal to E/Z0, # determines the insertion loss, from which it differs by an additive constant only, and where x=Z/Z0, while #=#0+# when Z=#, and # = #0-# when Z = 0. The Specification shows by expanding # in ascending powers of #, that to a close approximation where y = (Z-Z0) /(Z +Z0) Then #0 determines the normal characteristic A, Fig. 2, # determines the extreme departures from it represented by B, B<1>, and y# determines intermediate departures such as C, C<1>. Thus #0 and # are constants of the network including ZS and ZR, while y is determined by Z. Instead of being a variable resistance, Z may comprise a constant-resistance network M, Fig. 3, terminated by a variable resistance R. Then #0, determining the normal characteristic A, is unaffected by the insertion of the network M, but #, and consequently the deviating characteristics B, B<1>, C, C<1> are modified by it. Practical embodiments. In one group of embodiments typified by Fig. 6 (not shown) the variable impedance Z, Fig. 1, is a variable resistance R, Fig. 7, so that Z0 is R0, while the network N together with the terminal impedances Zs, RR, is represented by the pi network shown, in which Z11, Z21 are inverse impedances such that Z11.Z21=R<2>0. Figs. 8, 9 (not shown) show modifications of this arrangement. The network may be so designed that # is independent of frequency, and a constant-resistance network M, Fig. 3, is then inserted to give it the desired frequency variation, Fig. 10 (not shown) ; or the network N, Zs, ZR, Fig. 1, may comprise resistances only, Fig. 11 (not shown). In a further group of embodiments typified by Fig. 12 (not shown) the variable resistance R is in a shunt arm as in the arrangement shown in Fig. 13, which is inverse to that shown in Fig. 7. Modifications are shown in Figs. 14, 15 (not shown). The variable resistance R may be in series with or in shunt to a fixed impedance Z4, Figs. 16, 18 ; particular embodiments of this arrangement are shown in Figs. 17, 19 (not shown). In a further group of embodiments typified by Fig. 20 (not shown) the variable resistance R forms one diagonal of a bridge, the input and output terminals being in adjacent arms. Fig. 21 shows one embodiment comprising resistances and arbitrary shunt impedances forming a bridgedtee section and related to one another as shown. In a modification the resistances a.R0 and the variable resistance R are replaced by condensers, Fig. 22 (not shown) or inductances. Further embodiments of the bridge type are shown in Figs. 23, 24, 25 (not shown), the variable element R being in either the bridging diagonal or the shunt diagonal. Two constant-resistance networks M, Fig. 3, may be interposed between two adjustable resistances R, R<1>, Fig. 26, and two different arms of the bridge ; in this case by varying R<1> a family of extreme curves B, B<1>, Fig. 2, can be obtained, and for each member of the family a family of intermediate curves C, C<1> can be obtained by varying R. The Specification gives specific values for the impedance elements of an attenuator adapted to compensate for the temperature variation of the attenuation in a section of coaxial cable, Fig. 27 (not shown), and also of an attenuator, Fig. 29 (not shown), for use in a feed-back amplifier of the type which yields an overall characteristic inverse to the characteristic of the attenuator, so that the arrangement compensates distortion in a line having the same characteristic as the attenuator. The normal characteristic A, Fig. 2, is made to be that of a cable in which coaxial conductors are held apart by spaced insulators, and the temperature variations of the cable, which are known to produce characteristics of the type represented by C, C<1>, Fig. 2, are compensated by adjustment of the variable resistance R.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US61497A US2096027A (en) | 1936-01-30 | 1936-01-30 | Attenuation equalizer |
US165055A US2153743A (en) | 1936-01-30 | 1937-09-22 | Attenuation equalizer |
Publications (1)
Publication Number | Publication Date |
---|---|
GB469067A true GB469067A (en) | 1937-07-19 |
Family
ID=26724426
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB33693/36A Expired GB469067A (en) | 1936-01-30 | 1936-12-08 | Attenuation equalizers for electric transmission and like systems |
GB23837/38A Expired GB508341A (en) | 1936-01-30 | 1938-08-12 | Attenuation equalizers for electric transmission and like systems |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB23837/38A Expired GB508341A (en) | 1936-01-30 | 1938-08-12 | Attenuation equalizers for electric transmission and like systems |
Country Status (5)
Country | Link |
---|---|
US (2) | US2096027A (en) |
BE (1) | BE469067A (en) |
DE (1) | DE881528C (en) |
FR (2) | FR820760A (en) |
GB (2) | GB469067A (en) |
Families Citing this family (36)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2621253A (en) * | 1939-07-07 | 1952-12-09 | Int Standard Electric Corp | Electrical wave transmission system |
DE863362C (en) * | 1942-08-18 | 1953-01-15 | Siemens Ag | Frequency-dependent network with changeable frequency response |
GB645011A (en) * | 1947-08-11 | 1950-10-25 | Telephone Mfg Co Ltd | Improvements in and relating to electric impedance networks |
US2698420A (en) * | 1947-08-11 | 1954-12-28 | Telephone Mfg Co Ltd | Electric impedance network |
US2510283A (en) * | 1949-01-18 | 1950-06-06 | Bell Telephone Labor Inc | Variable equalizer |
NL149811B (en) * | 1949-04-12 | Procter & Gamble | PROCESS FOR PREPARING A METHYLENE DIPHOSPHONIC ACID COMPOUND WITH DETERGENT REINFORCING ACTION. | |
BE507449A (en) * | 1950-11-30 | |||
US2694184A (en) * | 1951-03-16 | 1954-11-09 | Bell Telephone Labor Inc | Equalizer |
US2738465A (en) * | 1951-05-05 | 1956-03-13 | Bell Telephone Labor Inc | Equalizer |
BE511542A (en) * | 1951-05-21 | |||
NO86475A (en) * | 1952-03-12 | |||
US2683777A (en) * | 1952-03-27 | 1954-07-13 | Bell Telephone Labor Inc | Automatic control of amplification in long distance transmission systems |
DE974866C (en) * | 1952-12-12 | 1961-05-18 | Siemens Ag | Arrangement for equalizing the temperature-dependent change in attenuation of lines |
US2867774A (en) * | 1952-12-17 | 1959-01-06 | Bell Telephone Labor Inc | Gain regulator for carrier systems |
BE527031A (en) * | 1953-03-16 | |||
FR1109931A (en) * | 1953-08-13 | 1956-02-03 | Muirhead & Co Ltd | Improvements to weakening networks |
NL182556B (en) * | 1953-11-04 | Pechiney Aluminium | METHOD FOR THE MANUFACTURE OF AL2O3 AGGLOMERATES WITH HIGH MECHANICAL RESISTANCE. | |
US2792552A (en) * | 1953-11-27 | 1957-05-14 | Bell Telephone Labor Inc | Attenuation equalizer |
FR1116277A (en) * | 1956-01-06 | 1956-05-07 | Cie Ind Des Telephones | Improvements to adjustable correctors |
US2926314A (en) * | 1956-07-23 | 1960-02-23 | Itt | Adjustable equalizer |
DE1242272B (en) * | 1959-01-13 | 1967-06-15 | Standard Elektrik Lorenz Ag | Arrangement for adjustable, frequency-dependent amplitude equalization in transmission systems |
FR1399686A (en) * | 1964-04-08 | 1965-05-21 | Active electric filters | |
GB1114949A (en) * | 1967-01-04 | 1968-05-22 | Standard Telephones Cables Ltd | Negative feedback amplifiers |
US3593211A (en) * | 1967-07-17 | 1971-07-13 | Nippon Electric Co | Adjustable attenuation equalizer |
DE1297154B (en) * | 1968-03-22 | 1969-06-12 | Siemens Ag | Ground equalizer for transmission systems |
FR2128152B1 (en) * | 1971-03-08 | 1974-02-15 | Lannionnais Electronique | |
US3890589A (en) * | 1971-06-30 | 1975-06-17 | Nippon Electric Co | Variable resistor |
US4027259A (en) * | 1976-06-14 | 1977-05-31 | Gte Automatic Electric Laboratories Incorporated | Line equalizer with differentially controlled complementary constant resistance networks |
DE3033762C2 (en) * | 1980-09-08 | 1983-04-14 | Siemens AG, 1000 Berlin und 8000 München | Equalizer circuit for communication signals |
DE3331006A1 (en) * | 1983-08-18 | 1985-03-07 | ANT Nachrichtentechnik GmbH, 7150 Backnang | TIME DISCRETE VARIABLE EQUALIZER |
IT1186383B (en) * | 1985-11-20 | 1987-11-26 | Gte Telecom Spa | REFINEMENTS FOR PIN DIODE ATTENUATORS |
US7394331B2 (en) | 2005-08-05 | 2008-07-01 | Evelina F Yeung | Programmable passive equalizer |
US8558636B2 (en) * | 2007-03-30 | 2013-10-15 | Intel Corporation | Package embedded equalizer |
US7760013B2 (en) * | 2008-02-06 | 2010-07-20 | Analog Devices, Inc. | Transadmittance and filter having a gain function |
US8976981B2 (en) * | 2010-10-07 | 2015-03-10 | Blackberry Limited | Circuit, system and method for isolating a transducer from an amplifier in an electronic device |
CN109412554B (en) * | 2018-09-22 | 2023-03-10 | 复旦大学 | Broadband high-precision numerical control active attenuator |
-
1936
- 1936-01-30 US US61497A patent/US2096027A/en not_active Expired - Lifetime
- 1936-12-08 GB GB33693/36A patent/GB469067A/en not_active Expired
-
1937
- 1937-01-30 FR FR820760D patent/FR820760A/en not_active Expired
- 1937-09-22 US US165055A patent/US2153743A/en not_active Expired - Lifetime
-
1938
- 1938-08-12 GB GB23837/38A patent/GB508341A/en not_active Expired
- 1938-09-21 FR FR49867D patent/FR49867E/en not_active Expired
-
1946
- 1946-11-08 BE BE469067D patent/BE469067A/xx unknown
-
1952
- 1952-09-25 DE DE1952W0003479 patent/DE881528C/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US2153743A (en) | 1939-04-11 |
FR820760A (en) | 1937-11-18 |
DE881528C (en) | 1953-07-02 |
FR49867E (en) | 1939-08-22 |
GB508341A (en) | 1939-06-29 |
US2096027A (en) | 1937-10-19 |
BE469067A (en) | 1946-12-31 |
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