GB519822A - Improvements in or relating to receivers for audio electric currents - Google Patents

Improvements in or relating to receivers for audio electric currents

Info

Publication number
GB519822A
GB519822A GB2800938A GB2800938A GB519822A GB 519822 A GB519822 A GB 519822A GB 2800938 A GB2800938 A GB 2800938A GB 2800938 A GB2800938 A GB 2800938A GB 519822 A GB519822 A GB 519822A
Authority
GB
United Kingdom
Prior art keywords
casing
pieces
pole
magnet
telephone
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
GB2800938A
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.)
Automatic Telephone and Electric Co Ltd
Original Assignee
Automatic Telephone and Electric 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 Automatic Telephone and Electric Co Ltd filed Critical Automatic Telephone and Electric Co Ltd
Priority to GB2800938A priority Critical patent/GB519822A/en
Publication of GB519822A publication Critical patent/GB519822A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R13/00—Transducers having an acoustic diaphragm of magnetisable material directly co-acting with electromagnet
    • H04R13/02—Telephone receivers

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Telephone Set Structure (AREA)

Abstract

519,822. Telephone receivers. AUTOMATIC TELEPHONE & ELECTRIC CO., Ltd., and ROSEBY, P. N. Sept. 26, 1938, No. 28009. [Class 40 (iv)] An auxiliary permanent magnet 13, Fig. 1, is. inserted in a telephone receiver containing an operative permanent magnet 10, Fig. 2, in order to reduce the external magnetic field. The magnet 10 is a short bar of "Alnico" or - other magnetic material of high coercivity lying between L-shaped pole-pieces 7 around which the coils 11 are arranged. Lateral extensions of the pole-pieces support on one side a clip 14 for the auxiliary magnet 13 and on the other side a bracket 12 for the strain cord of the leads, which are attached to terminals 9 secured with the pole-pieces to the base of the casing by bolts 8. The outside field is still further reduced by means of liners 5, 6 of magnetic material around and at the back of the receiver and the magnetic diaphragm 4 in front. An inset casing 2 is of light metal, e.g. aluminium, and the outer parts 1, 3 of the casing are of thin material known under the Registered Trade Mark "Bakelite."
GB2800938A 1938-09-26 1938-09-26 Improvements in or relating to receivers for audio electric currents Expired GB519822A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2800938A GB519822A (en) 1938-09-26 1938-09-26 Improvements in or relating to receivers for audio electric currents

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2800938A GB519822A (en) 1938-09-26 1938-09-26 Improvements in or relating to receivers for audio electric currents

Publications (1)

Publication Number Publication Date
GB519822A true GB519822A (en) 1940-04-08

Family

ID=10268808

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2800938A Expired GB519822A (en) 1938-09-26 1938-09-26 Improvements in or relating to receivers for audio electric currents

Country Status (1)

Country Link
GB (1) GB519822A (en)

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