GB791295A - Improvements in or relating to electro-magnetic telephones - Google Patents

Improvements in or relating to electro-magnetic telephones

Info

Publication number
GB791295A
GB791295A GB21008/55A GB2100855A GB791295A GB 791295 A GB791295 A GB 791295A GB 21008/55 A GB21008/55 A GB 21008/55A GB 2100855 A GB2100855 A GB 2100855A GB 791295 A GB791295 A GB 791295A
Authority
GB
United Kingdom
Prior art keywords
cover
diaphragm
magnetic
electro
relating
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
GB21008/55A
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.)
Philips Electrical Industries Ltd
Original Assignee
Philips 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 Philips Electrical Industries Ltd filed Critical Philips Electrical Industries Ltd
Publication of GB791295A publication Critical patent/GB791295A/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

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Telephone Set Structure (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)

Abstract

791,295. Microphones and receivers. PHILIPS ELECTRICAL INDUSTRIES, Ltd. July 20, 1955 [July 23, 1954], No. 21008/55. Class 40 (4). In an electromagnetic telephone instrument in which a magnetic diaphragm 2 is associated with wound pole pieces 5, 6 of a magnet 4, the pole pieces project through apertures in a cover 8 which are sealed by a foil disc 9 of non- magnetic material such as aluminium or acetobutyrate. This disc is positioned between the diaphragm and the cover, and restsrict the acoustic path between the rear of the diaphragm and a closed chamber 1 to an opening 3 in the foil and cover which is filled with an acoustic resistance material.
GB21008/55A 1954-07-23 1955-07-20 Improvements in or relating to electro-magnetic telephones Expired GB791295A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL331379X 1954-07-23

Publications (1)

Publication Number Publication Date
GB791295A true GB791295A (en) 1958-02-26

Family

ID=19784383

Family Applications (1)

Application Number Title Priority Date Filing Date
GB21008/55A Expired GB791295A (en) 1954-07-23 1955-07-20 Improvements in or relating to electro-magnetic telephones

Country Status (5)

Country Link
US (1) US2852627A (en)
BE (1) BE540009A (en)
CH (1) CH331379A (en)
GB (1) GB791295A (en)
NL (1) NL85836C (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3179749A (en) * 1960-03-03 1965-04-20 Milton L Snow Telephone instrument controlling device
NL274625A (en) * 1961-02-10

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1644788A (en) * 1922-12-08 1927-10-11 Western Electric Co Acoustic device
US2249161A (en) * 1939-05-19 1941-07-15 Bell Telephone Labor Inc Electroacoustic device

Also Published As

Publication number Publication date
NL85836C (en)
CH331379A (en) 1958-07-15
US2852627A (en) 1958-09-16
BE540009A (en)

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