Renseignements généraux

Nº de série

S/O

Nº de partie

1

Nombre total de parties

1

Ou

S/O

Brevets

S/O

Description générale

CAST IRON FRAME, STEEL MAGNET ASSEMBLY, BRASS CLAMPING BARS, COTTON COVERED MAGNET WIRE SOLINOIDS

Dimensions

Remarque : Cette information reflète la taille générale pour l’entreposage et ne représente pas nécessairement les véritables dimensions de l’objet.

Longueur

15,0 cm

Largeur

11,0 cm

Hauteur

6,5 cm

Épaisseur

S/O

Poids

S/O

Diamètre

S/O

Volume

S/O

Lexique

Groupe

Communications

Catégorie

Téléphonie

Sous-catégorie

S/O

Fabricant

Ou

Inconnu

Pays

United States of America

État/province

Inconnu

Ville

Inconnu

Contexte

Pays

Amérique du Nord

État/province

Inconnu

Période

1877 TO 1887

Canada

PATENTED BY ALEXANDER GRAHAM BELL IN 1877, BASED ON RESEARCH CARRIED OUT AT BRANTFORD, ON. & BOSTON, MA.

Fonction

USED TO CONVERT VOICE SOUNDS INTO VARYING ELECTRIC CURRENT BY THE ACTION OF A STEEL DIAPHRAGM VARYING THE MAGNETIC FIELD SUPPLIED BY THE LARGE MAGNET ASSEMBLY. IT COULD ALSO BE USED AS A RECEIVER WITH VARYING CURRENT APPLIED TO THE COILS WHICH WOULD INCREASE & DECREASE THE MAGNETIC FIELD & THUS CAUSE THE STEEL DIAPHRAGM TO MOVE, PRODUCING SOUND.

Technique

FIRST TYPE OF TELEPHONE TRANSMITTER IN COMMERCIAL SERVICE, 1877-1878. IT CONSISTED OF A METAL DIAPHRAGM FIXED IN THE FIELD OF A PERMANENT MAGNET WITH A VOICE COIL WOUND AROUND THE MAGNET'S POLES. VIBRATION OF THE DIAPHRAGM BY SOUND WAVES CAUSED A VARIATION OF THE MAGNETIC FIELD & INTRODUCED A VARYING CURRENT IN THE VOICE COIL, WHICH WAS TRANSMITTED OVER A TELEPHONE WIRE. IT WAS SOON SUPERSEDED BY THE CARBON VARIABLE RESISTANCE TRANSMITTER, WHICH PROVIDED MORE POWERFUL SIGNALS.

Notes sur la région

Inconnu

Détails

Marques

'36' WRITTEN IN WHITE PAINT ON FRONT OF CASTING

Manque

DIAGRHAM, MISC. HARDWARE AND WALL MOUNTING CASE

Fini

FRAME, BLACK ENAMEL

Décoration

S/O