GB529869A - Improvements in telephone transmitters of the carbon granule type - Google Patents

Improvements in telephone transmitters of the carbon granule type

Info

Publication number
GB529869A
GB529869A GB16975/39A GB1697539A GB529869A GB 529869 A GB529869 A GB 529869A GB 16975/39 A GB16975/39 A GB 16975/39A GB 1697539 A GB1697539 A GB 1697539A GB 529869 A GB529869 A GB 529869A
Authority
GB
United Kingdom
Prior art keywords
granules
insulator
diaphragm
closure
plate
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
GB16975/39A
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Publication of GB529869A publication Critical patent/GB529869A/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
    • H04R21/00—Variable-resistance transducers
    • H04R21/02—Microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R21/00—Variable-resistance transducers
    • H04R21/02—Microphones
    • H04R21/021—Microphones with granular resistance material

Landscapes

  • Physics & Mathematics (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)

Abstract

529,869. Microphones. STANDARD TELEPHONES & CABLES, Ltd. June 9, 1939, No. 16975. Convention date, June 18, 1938. [Class 40 (iv)] In a telephone transmitter of the granulated carbon type, the granules are compressed between a conical face 33a on the metal back plate 29 and a correspondingly dished surface 20 carried on a ring 19 secured to the diaphragm 12. The granules are retained by a silk closure 24 and an insulator which may be in one piece or in two parts 25, 27 ; the faces of the closure 24 and insulator are conical so that sideways movement of the granules during compression is opposed by the decrease in the volume of the part of the chamber between these two faces. In one form the silk closure is flat but the insulator is coned. The granules are fed through holes 37 in the plate 29. The whole is mounted in a metal box 10 with insulation 15, 34 for the diaphragm and plate. A moisture proof screen 18 and a protective cover may be provided in front of the diaphragm.
GB16975/39A 1938-06-18 1939-06-09 Improvements in telephone transmitters of the carbon granule type Expired GB529869A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US214460A US2225488A (en) 1938-06-18 1938-06-18 Impulse translating apparatus

Publications (1)

Publication Number Publication Date
GB529869A true GB529869A (en) 1940-11-29

Family

ID=22799157

Family Applications (1)

Application Number Title Priority Date Filing Date
GB16975/39A Expired GB529869A (en) 1938-06-18 1939-06-09 Improvements in telephone transmitters of the carbon granule type

Country Status (2)

Country Link
US (1) US2225488A (en)
GB (1) GB529869A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2527159A (en) * 1947-04-26 1950-10-24 Bell Telephone Labor Inc Telephone transmitter with radial slots in the carbon chamber
DE942517C (en) * 1952-08-30 1956-05-03 Lorenz C Ag Carbon microphone with one fixed and one movable electrode with a secondary electrode
US2967914A (en) * 1955-06-02 1961-01-10 Automatic Elect Lab Telephone transmitter

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL70196C (en) * 1947-10-31
US2532741A (en) * 1947-10-31 1950-12-05 Bell Telephone Labor Inc Microphone with opposite electrodes being of varying and constant curvature
US2562526A (en) * 1949-12-01 1951-07-31 Stromberg Carlson Co Telephone transmitter
US2607859A (en) * 1950-12-01 1952-08-19 Bell Telephone Labor Inc Telephone transmitter
US3103559A (en) * 1960-06-24 1963-09-10 Waterproof electrostrictive inertial type microphone

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2527159A (en) * 1947-04-26 1950-10-24 Bell Telephone Labor Inc Telephone transmitter with radial slots in the carbon chamber
DE942517C (en) * 1952-08-30 1956-05-03 Lorenz C Ag Carbon microphone with one fixed and one movable electrode with a secondary electrode
US2967914A (en) * 1955-06-02 1961-01-10 Automatic Elect Lab Telephone transmitter

Also Published As

Publication number Publication date
US2225488A (en) 1940-12-17

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