US2661398A - Stabilized thermionic amplifier - Google Patents

Stabilized thermionic amplifier Download PDF

Info

Publication number
US2661398A
US2661398A US78804A US7880449A US2661398A US 2661398 A US2661398 A US 2661398A US 78804 A US78804 A US 78804A US 7880449 A US7880449 A US 7880449A US 2661398 A US2661398 A US 2661398A
Authority
US
United States
Prior art keywords
valves
pair
valve
anode
cathode
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 - Lifetime
Application number
US78804A
Other languages
English (en)
Inventor
Cooper Victor James
Nixon John Esmonde Arthur
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Marconis Wireless Telegraph Co Ltd
BAE Systems Electronics Ltd
Original Assignee
Marconi Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Marconi Co Ltd filed Critical Marconi Co Ltd
Application granted granted Critical
Publication of US2661398A publication Critical patent/US2661398A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/42—Amplifiers with two or more amplifying elements having their DC paths in series with the load, the control electrode of each element being excited by at least part of the input signal, e.g. so-called totem-pole amplifiers
    • H03F3/44—Amplifiers with two or more amplifying elements having their DC paths in series with the load, the control electrode of each element being excited by at least part of the input signal, e.g. so-called totem-pole amplifiers with tubes only

Definitions

  • This invention relates to thermionic valve am plifiers and has for its object to provide improved amplifiers adapted to handle a wide band of signals and give good linearity of response, good gain and a low value of output impedance.
  • the invention has been primarily designed for use in connection with the amplification of television signals for modulated carrier television transmitters of high power.
  • a thermionic valve amplifier comprises two pairs of valves, each pair being in a series circuit across an anode potential source, means for applying signals to be amplified to a control electrode of that valve of the first pair which is further from the positive terminal of the anode potential source, means for coupling a point between the valves of the first pair to the control electrode of that valve of said pair which is nearer said positive terminal, means for coupling a point between the valves of the first pair to a control electrode of that valve of the second pair which is nearer to said positive terminal, means for coupling the output electrode of the last mentioned valve to a control electrode of the remaining valve of said second pair and means for taking amplified output from a point between the valves of the second pair.
  • an impedance is included in series between the two valves of the first pair and the point between said pair which is coupled to a control electrode of the more positive valve in the second pair is constituted by the cathode of the more positive valve of the first pair. It is, how ever, possible, though not usually preferred, to constitute the said point by the anode of the more negative valve of the first pair or by a point on an impedance in series between the valves of said pair.
  • a first pair of valves comprising two valves Vi, V2 of which the anode of VI is connected to the positive terminal of an HT source (not shown) and the cathode of V2 is connected to the negative terminal.
  • a resistance RI connects the cathode of Vi to the anode of V2 and, a bias source or network is provided to bias the grid of VI positive with respect to the anode of V2.
  • This bias may be obtained in any convenient way: as shown a resistance R3 is connected between a tap on RI and the grid of Vi.
  • a coupling condenser Kl is connected between the grid of VI and the anode of V2. If desired the bias source may be adjustable.
  • a condenser K2 connects GB to HT.
  • a second pair of valves consisting of the valves V3, V4 is also provided.
  • the valve V3 has its anode connected to HT+ through a resistance R2 and Vi has its anode connected to the cathode of V3 and its cathode connected to HT-.
  • the cathode of VI is connected to the grid of V3 and the anode of V3 is connected through a blocking condenser K3 to the grid of V4.
  • Valve V4 receives bias through resistance R5 from terminal -GB4 which is connected to HT through condenser K4. Amplified output is taken at out from between the anode of V4 and the cathode thereof.
  • This arrangement gives improved amplitude linearity, reduced output impedance and has improved reactive and non-linear current handling capabilities as compared to conventional amplifiers. Also it has a better power conversion efiiciency as compared to a conventional class A amplifier and is more suitable for the amplification of very wide bands of frequencies such as a television signal band. It may be shown mathematically that the arrangement of the series pair of valves VI and V2 improves amplitude linearity of response due to non-linearity of the valve characteristics towards current cut-01f, the improvement being by an amount equivalent to raising the anode resistance of V2 by the difference between the combined D. C. resistance of VI and RI and the A. C. impedance of V!
  • the second pair of valves V3, V4 produces an output impedance lower than that attainable with a conventional cathode follower arrangement, the improvement being proportional to the magnitude of R2 and the amplification factor of V4.
  • valves employed may be any of a variety of suitable types.
  • Fig. 1 only those electrodes which are necessary to the invention are shown.
  • the valves may, however, be triodes, screen grid valves, pentodes or of any desired suitable types. Further, as already stated, any one of the valves may be replaced by a number in parallel.
  • the valves VI, V2, V 3, V 3 were constituted by combinations of valves all of the same type having an amplification factor of about 14 and an anode impedance of about 500 ohms.
  • valve V3 was constituted by four valves with like electrodes connected together; and the valve V4 was constituted by three valves with like electrodes connected together.
  • This particular arrangement gave an overall gain of 10 or more with a frequency response extending to over 5 megacycles per second and an output impedance of less than three ohms.
  • the output amplitude level remained constant at about 490 volts R. M. S. when working into a reactive load of 150 ohms.
  • the high tension voltage was 3008 volts and the high tension power input lessthan l0 kw.
  • Figs. 2 and 3 show two modifications of Fig. I wherein the arrangement is provided with negative Iced back. It is thought that these two figures will be largely self-explanatory in view of the description of Fig. 1 already given.
  • the input is applied via an additional valve V,
  • connection FE between the anode of which the anode of V l provides the feed back path.
  • Fig. 3 the negative feed back path. is completed through the circuit FB between the anode.
  • Vd Vd and the grid of V2. Both these arrangements are capable of handling wide bands of frequencies.
  • a thermionic valve amplifier including two pairs of valves each having at least a cathode
  • a control electrode and an anode a common anode potential source for all four valves
  • means connecting the valves of the first pair in a series circuit across said anode potential source said circuit including a first connection between the cathode of one of the valves of said first pair and the anode of the other of the valves of said first pair including a resistor connected at one end to said last mentioned cathode and at the other end to said last mentioned anode, a tap intermediate the ends of said resistor connected to the control electrode of the first mentioned valve of said first pair of valves, a coupling condenser between the anode of the other valve of said first pair of valves and the control grid of the aforementioned valve of said first pair of valves, means for applying signals to be amplified to a control electrode of said other valve of said first pair, means con necting the valves of the second pair in a second series circuit across said anode potential source, said circuit including a second series connection between the cathode of one of the valves of
  • An amplifier as set forth in claim 1 which includes an additional valve having at least a cathode, a control grid and an anode, additional valve being interposed between the other valve of said first pair of valves and the means for applying signals to be amplified, the cathode of said additional valve being connected with the control grid of said other valve of first pair of valves and the anode of said additional valve being connected with the anode of the other valve of said second pair of valves for providing negative feed-back in said amplifier.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)
US78804A 1948-05-20 1949-02-28 Stabilized thermionic amplifier Expired - Lifetime US2661398A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB276293X 1948-05-20
GB50149X 1949-01-05

Publications (1)

Publication Number Publication Date
US2661398A true US2661398A (en) 1953-12-01

Family

ID=26239528

Family Applications (1)

Application Number Title Priority Date Filing Date
US78804A Expired - Lifetime US2661398A (en) 1948-05-20 1949-02-28 Stabilized thermionic amplifier

Country Status (4)

Country Link
US (1) US2661398A (fr)
CH (1) CH276293A (fr)
FR (1) FR985674A (fr)
GB (1) GB657312A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2764643A (en) * 1954-03-23 1956-09-25 Frank H Mcintosh Oscillators
US2783314A (en) * 1952-05-29 1957-02-26 John H Reaves Square-wave amplifier circuits
US2820140A (en) * 1954-01-05 1958-01-14 Rca Corp Code converter
US3028451A (en) * 1956-11-01 1962-04-03 Automatic Elect Lab Transistor amplifier
US3038125A (en) * 1958-04-18 1962-06-05 Philips Corp Negative feedback circuit
US3049672A (en) * 1958-10-20 1962-08-14 Sperry Rand Corp Voltage generating circuit having an output trigger voltage that rises abruptly at apredetermined time

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1029878B (de) * 1955-04-01 1958-05-14 Philips Nv Schaltung zur Verstaerkung mittels zweier vom Speisestrom in Reihe durchflossener Roehren

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2310342A (en) * 1940-11-29 1943-02-09 Rca Corp Balanced direct and alternating current amplifiers
US2358428A (en) * 1940-09-07 1944-09-19 Emi Ltd Thermionic valve amplifier circuit arrangement
US2438960A (en) * 1940-11-29 1948-04-06 Rca Corp Balanced amplifier
US2543819A (en) * 1948-05-14 1951-03-06 John E Williams Push-pull differential electronic amplifier

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2358428A (en) * 1940-09-07 1944-09-19 Emi Ltd Thermionic valve amplifier circuit arrangement
US2428295A (en) * 1940-09-07 1947-09-30 Emi Ltd Thermionic valve amplifier circuit arrangement
US2310342A (en) * 1940-11-29 1943-02-09 Rca Corp Balanced direct and alternating current amplifiers
US2438960A (en) * 1940-11-29 1948-04-06 Rca Corp Balanced amplifier
US2543819A (en) * 1948-05-14 1951-03-06 John E Williams Push-pull differential electronic amplifier

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2783314A (en) * 1952-05-29 1957-02-26 John H Reaves Square-wave amplifier circuits
US2820140A (en) * 1954-01-05 1958-01-14 Rca Corp Code converter
US2764643A (en) * 1954-03-23 1956-09-25 Frank H Mcintosh Oscillators
US3028451A (en) * 1956-11-01 1962-04-03 Automatic Elect Lab Transistor amplifier
US3038125A (en) * 1958-04-18 1962-06-05 Philips Corp Negative feedback circuit
US3049672A (en) * 1958-10-20 1962-08-14 Sperry Rand Corp Voltage generating circuit having an output trigger voltage that rises abruptly at apredetermined time

Also Published As

Publication number Publication date
GB657312A (en) 1951-09-19
CH276293A (fr) 1951-06-30
FR985674A (fr) 1951-07-23

Similar Documents

Publication Publication Date Title
US2276565A (en) Limiting amplifier
US2120823A (en) Coupling means for thermionic valve circuits
US2200055A (en) High impedance attenuator
US2661398A (en) Stabilized thermionic amplifier
US2273997A (en) Negative feedback amplifier
US2710312A (en) Ultra linear amplifiers
US2324279A (en) Amplifier
US2638512A (en) Direct coupled amplifying system
US2778883A (en) Parallel amplifying system
US2464594A (en) Phase and amplitude control circuit for wide band amplifiers
US3247462A (en) Balanced paraphase amplifier including a feed forward path
US2525632A (en) Low-frequency amplifier
US2178012A (en) Thermionic valve circuits
US2154200A (en) Voltage regulator device
US2338410A (en) Push-pull amplifier
US2292136A (en) Push-pull resistance coupled amplifier
US2802070A (en) Stabilized feedback amplifier
US2400734A (en) Direct coupled amplifier
US2547213A (en) Negative feedback amplifier
US2338342A (en) Amplifier circuit
US2721909A (en) Gain control circuit arrangements
US2505024A (en) Wave translating circuits
US1946047A (en) Thermionic amplifier
US2361282A (en) Push-pull electron tube system
US2156659A (en) Amplifier device