telegraph relay
Datecirca 1930
Inventory Number1997-1-0603
ClassificationRelay
Subject
Maker
Leach Relay Company
1919-present
Cultural Region
Place of Origin
Dimensions5 × 14.3 × 9.1 cm (1 15/16 × 5 5/8 × 3 9/16 in.)
Material
DescriptionTelegraph relay on a black rectangular base. Two black cylinders (an electromagnet) lie in the centre of the base, a black metal plate connecting them in the front and back. A thick, copper-colored screw runs from the back plate to a small cylinder, a rod with two adjustment dials extending out of the other end of the cylinder. A binding post stands to either side of the cylinder. A rod with two adjustment dials extends out of the front plate, through a thin metal rectangle. A coil is wrapped around the rod on the other side of the rectangle, ending in an adjustment dial. A binding post stands to either side of the dial.
Signedon base: LEACH RELAY CO. L.A.
Inscribedon base: 6 VOLTS D.C.
FunctionThis telegraphic instrument was used as 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
U.S. Electrical Supplies
Date: 1910-1920
Object number: 1997-1-0578
Leach Relay Company
Date: 1890-1930
Object number: RS0531