GB206620A - Improvements in amplifying arrangements for telephonic currents - Google Patents

Improvements in amplifying arrangements for telephonic currents

Info

Publication number
GB206620A
GB206620A GB2353422A GB2353422A GB206620A GB 206620 A GB206620 A GB 206620A GB 2353422 A GB2353422 A GB 2353422A GB 2353422 A GB2353422 A GB 2353422A GB 206620 A GB206620 A GB 206620A
Authority
GB
United Kingdom
Prior art keywords
amplifier
primary
lead
resistance
middle point
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
Application number
GB2353422A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to GB2353422A priority Critical patent/GB206620A/en
Publication of GB206620A publication Critical patent/GB206620A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H04B1/54—Circuits using the same frequency for two directions of communication
    • H04B1/58—Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)

Abstract

206,620. Strauss, S. Aug. 30, 1922. Thermionic amplifiers.-In an amplifier for use at a telephone substation or private branch exchange, in which one or two thermionic valves in cascade may be switched in at will, the middle point of the primary or the input transformer is connected to the secondary of the output transformer, and to the source of filament heating current, in order to prevent whistling in the receiver. Fig. 1 shows substation apparatus in a local battery system, with switches D, H, I, J for connecting up the amplifier. The middle point F of the primary PI of the input transformer is connected to the secondary S3 of the output transformer by a lead O, and the resistance R balances the resistance of the line so that only a small current flows through the winding S. One or two of the valves V, V1 may be used according to the position of a multiple-contact key Ta. The invention is also described with reference to two standard central battery systems, in which the amplifier battery may be used for feeding the microphone. Fig. 6 shows the application to a P.B.X., the amplifier (not shown) being included in the cord circuit, and an additional wire L3 being provided for each subscriber corresponding to the lead O, Fig. 1, with suitable plugs.
GB2353422A 1922-08-30 1922-08-30 Improvements in amplifying arrangements for telephonic currents Expired GB206620A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2353422A GB206620A (en) 1922-08-30 1922-08-30 Improvements in amplifying arrangements for telephonic currents

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2353422A GB206620A (en) 1922-08-30 1922-08-30 Improvements in amplifying arrangements for telephonic currents

Publications (1)

Publication Number Publication Date
GB206620A true GB206620A (en) 1923-11-15

Family

ID=10197179

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2353422A Expired GB206620A (en) 1922-08-30 1922-08-30 Improvements in amplifying arrangements for telephonic currents

Country Status (1)

Country Link
GB (1) GB206620A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2160312A (en) * 1984-04-13 1985-12-18 South African Inventions Adjuvant for immunisation

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2160312A (en) * 1984-04-13 1985-12-18 South African Inventions Adjuvant for immunisation

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