GB881370A - Improvements relating to modulators for telecommunication systems - Google Patents

Improvements relating to modulators for telecommunication systems

Info

Publication number
GB881370A
GB881370A GB1668558A GB1668558A GB881370A GB 881370 A GB881370 A GB 881370A GB 1668558 A GB1668558 A GB 1668558A GB 1668558 A GB1668558 A GB 1668558A GB 881370 A GB881370 A GB 881370A
Authority
GB
United Kingdom
Prior art keywords
ringing current
current
impedances
modulators
ringing
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
GB1668558A
Inventor
Alan Stanford Wickham
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.)
Associated Electrical Industries Ltd
Original Assignee
Associated Electrical Industries 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 Associated Electrical Industries Ltd filed Critical Associated Electrical Industries Ltd
Priority to GB1668558A priority Critical patent/GB881370A/en
Publication of GB881370A publication Critical patent/GB881370A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C1/00—Amplitude modulation
    • H03C1/08—Amplitude modulation by means of variable impedance element
    • H03C1/10—Amplitude modulation by means of variable impedance element the element being a current-dependent inductor

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

881,370. Telephone transmission systems. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. May 22, 1959 [May 23, 1958], No. 16685 /58. Class 40 (4). [Also in Group XL (c)] Dialling impulses (D.C.) and low-frequency ringing current (17 c.p.s.) are converted into alternating current signals (8200 c.p.s.) by means of a magnetic modulator (see Group XL (c)). The impulsing circuit is connected to terminals 14, 15 ; the ringing current is rectified and applied to 16, 17 ; and the 8200 c.p.s. source is cormected to 10, 11. Normally the impedances of the controlled windings 2A, 2B are high and no output is obtained at 12, 13. However, for the duration of each impulse, and while ringing current is being received the direct current flowing in the controlling windings 1A(I), 1B(I) and 1A(II), 1B(II) respectively, lowers the impedances of 2A and 2B, and 8200 c.p.s. signals appear at 12, 13. In a modification, the ringing current is applied directly to 16, 17 so that a burst of output appears once per half-cycle of the ringing current.
GB1668558A 1958-05-23 1958-05-23 Improvements relating to modulators for telecommunication systems Expired GB881370A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1668558A GB881370A (en) 1958-05-23 1958-05-23 Improvements relating to modulators for telecommunication systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1668558A GB881370A (en) 1958-05-23 1958-05-23 Improvements relating to modulators for telecommunication systems

Publications (1)

Publication Number Publication Date
GB881370A true GB881370A (en) 1961-11-01

Family

ID=10081794

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1668558A Expired GB881370A (en) 1958-05-23 1958-05-23 Improvements relating to modulators for telecommunication systems

Country Status (1)

Country Link
GB (1) GB881370A (en)

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