plug board with square plugs
Inventory Number2012-1-0023
ClassificationPlug Board
Subject
Cultural Region
Place of Origin
Place of Use
Dimensions12 × 27 × 8.2 cm (4 3/4 × 10 5/8 × 3 1/4 in.)
Material
DescriptionRectangular wooden case with rectangular black top panel.
Mounted on top panel undercut brass blocks shaped to accommodate thirteen interchangeable brass shorting plugs which have rounded square heads. Marked 0-40, and "INF" at end opposite the binding posts.
There are two more binding posts on one end of the rectangular formation.
Mounted on top panel undercut brass blocks shaped to accommodate thirteen interchangeable brass shorting plugs which have rounded square heads. Marked 0-40, and "INF" at end opposite the binding posts.
There are two more binding posts on one end of the rectangular formation.
Signedunsigned
FunctionThe most accurate method of measuring resistance is by comparison with a known resistance, and for this and other purposes, boxes of accurately adjusted resistances with convenient arrangements for connecting any number of them in series are largely employed. Two types in use are the plug and sliding-contact types. In the former, the resistance coils are connected between brass blocks, and plugs with ebonite tops are provided which on insertion into the tapered holes between the blocks short circuit the respective coils, so that the total resistance between the terminals is the sum of the resistances of the coils unplugged.
website.
website.
Date: 1890-1930
Object number: RS0505
Hartmann & Braun AG
Date: 1900-1920
Accessories: plugs (8)
Object number: 1997-1-0399
Hartmann & Braun AG
Date: circa 1920
Accessories: 6 plugs
Object number: 1997-1-0400
Date: 1920
Accessories: a--has clip; b--no clip
Object number: 1998-1-0648a,b
Leeds & Northrup Company
Date: circa 1938
Accessories: plugs (6)
Object number: 1997-1-0196