FR548289A - Microphones téléphoniques - Google Patents

Microphones téléphoniques

Info

Publication number
FR548289A
FR548289A FR548289DA FR548289A FR 548289 A FR548289 A FR 548289A FR 548289D A FR548289D A FR 548289DA FR 548289 A FR548289 A FR 548289A
Authority
FR
France
Prior art keywords
telephone microphones
microphones
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
Other languages
English (en)
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.)
DICTOGRAPH PRODUCTS CORP
Original Assignee
DICTOGRAPH PRODUCTS CORP
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 DICTOGRAPH PRODUCTS CORP filed Critical DICTOGRAPH PRODUCTS CORP
Application granted granted Critical
Publication of FR548289A publication Critical patent/FR548289A/fr
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; 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)
  • Details Of Audible-Bandwidth Transducers (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
FR548289D 1921-04-14 1922-03-07 Microphones téléphoniques Expired FR548289A (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US461283A US1551723A (en) 1921-04-14 1921-04-14 Transmitter

Publications (1)

Publication Number Publication Date
FR548289A true FR548289A (fr) 1923-01-11

Family

ID=9738041

Family Applications (1)

Application Number Title Priority Date Filing Date
FR548289D Expired FR548289A (fr) 1921-04-14 1922-03-07 Microphones téléphoniques

Country Status (4)

Country Link
US (1) US1551723A (fr)
DE (1) DE379111C (fr)
FR (1) FR548289A (fr)
GB (1) GB190655A (fr)

Also Published As

Publication number Publication date
GB190655A (en) 1922-12-28
DE379111C (de) 1923-08-14
US1551723A (en) 1925-09-01

Similar Documents

Publication Publication Date Title
FR553457A (fr) Téléphone
FR548289A (fr) Microphones téléphoniques
FR556412A (fr) Perfectionnements aux téléphones haut-parleurs
FR545459A (fr) Avertisseur auditif
FR547478A (fr) Micro-téléphone combiné
FR585125A (fr) Perfectionnements aux casques téléphoniques
FR541706A (fr) Microphone sélectif
FR552515A (fr) Téléphones-jouets
SU4304A1 (ru) Телефонна трансл ци
FI8381A (fi) Telefontalapparat
FR26494E (fr) Matériel téléphonique
FR29698E (fr) Poste-téléphonique haut-parleur
FR555546A (fr) Perfectionnements aux écouteurs téléphoniques
FI8473A (fi) Barkningsjärn
FI8444A (fi) Strömbrytare
FR545031A (fr) Machine parlante
FR544081A (fr) Téléphone électrostatique
FR540090A (fr) Perfectionnements apportés aux réseaux téléphoniques
FI8728A (fi) Fonografisk dikteringsapparat
DK31706C (da) Telefon- eller Mikrotelefonbærer.
FR540862A (fr) Cabine téléphonique
DK31804C (da) Indstillelig Telefon- eller Mikrotelefonbærer.
ES77611A1 (es) Arrollamiento de hilos telefónico.
DK27854C (da) Mikrofon.
DK30098C (da) Mikrofon.