telegraph relay
Date1890-1910
Inventory Number1997-1-0591
ClassificationTelegraph Relay
Subject
Attributed to
J. H. Bunnell & Company
1878-present
Cultural Region
Place of Origin
Dimensions7.2 × 16.6 × 9 cm (2 13/16 × 6 9/16 × 3 9/16 in.)
Material
DescriptionTelegraph relay mounted on a rectangular wooden base, the latter sitting on a metal plate. Two black metal cylinders (an electromagnet) sit in the middle of the base. An L-shaped piece of metal runs behind and above the cylinders, extending into an arc in front of them. A metal plate sits in front of the cylinders, wide at the bottom with a thin piece extending up into the arc. There is a hook on the metal plate, to which a spring is attached, a string connecting the other end of the spring to a metal post on the front of the base. There are two pieces of metal on the back of the base, and two on the front-right, for connection to a battery.
Signedunsigned
FunctionThis telegraphic instrument was used as a control relay. It could be used to control the current flow between other telegraphic instruments and switchboards. When a current flowed through the magnet, it would attract the metal plate in front. When the current ceased to flow, the plate would return to its resting position. The effect was that of opening and closing a switch.
Burnell Telephone and Electric Company
Date: circa 1905
Object number: 1997-1-0571
