GB866227A - Improvements in tone receivers - Google Patents

Improvements in tone receivers

Info

Publication number
GB866227A
GB866227A GB1330958A GB1330958A GB866227A GB 866227 A GB866227 A GB 866227A GB 1330958 A GB1330958 A GB 1330958A GB 1330958 A GB1330958 A GB 1330958A GB 866227 A GB866227 A GB 866227A
Authority
GB
United Kingdom
Prior art keywords
resistor
transistor
transformer
tuned
circuit
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
GB1330958A
Inventor
Edward Harold Norman
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.)
Ericsson Telephones Ltd
Original Assignee
Ericsson Telephones 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 Ericsson Telephones Ltd filed Critical Ericsson Telephones Ltd
Priority to GB1330958A priority Critical patent/GB866227A/en
Publication of GB866227A publication Critical patent/GB866227A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J1/00—Frequency-division multiplex systems
    • H04J1/02—Details
    • H04J1/14—Arrangements providing for calling or supervisory signals

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

866,227. Voice immunity circuits. ERICSSON TELEPHONES Ltd. July 24, 1959 [April 26, 1958], No. 13309/58. Class 40 (4). A normally conducting transistor 23 is cut off in response to a signalling tone which in energizing a potential divider comprised by resistor 14 and circuit 16, 17, tuned to the signal tone frequency, finds high impedance across the tuned circuit and consequently provides a positive bias on the transistor base, whereas if non- signal tone frequencies occur the voltage drop across resistor 14 provides a negative bias to hold transistor 23 conducting. Incoming signals are applied to the primary of transformer 10 and although the guard voltage may be taken from across resistor 14 it may also include part of the secondary winding of transformer 10, as shown.
GB1330958A 1958-04-26 1958-04-26 Improvements in tone receivers Expired GB866227A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1330958A GB866227A (en) 1958-04-26 1958-04-26 Improvements in tone receivers

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1330958A GB866227A (en) 1958-04-26 1958-04-26 Improvements in tone receivers

Publications (1)

Publication Number Publication Date
GB866227A true GB866227A (en) 1961-04-26

Family

ID=10020619

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1330958A Expired GB866227A (en) 1958-04-26 1958-04-26 Improvements in tone receivers

Country Status (1)

Country Link
GB (1) GB866227A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3226563A (en) * 1961-03-08 1965-12-28 John C Lovci Teletype current supply system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3226563A (en) * 1961-03-08 1965-12-28 John C Lovci Teletype current supply system

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