Wheatstone Bridge

WheatstoneBridge-Phys(storage)-0.JPG
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WheatstoneBridge-Phys(storage)-base.JPG

Title

Wheatstone Bridge

Subject

electricity, physics

Description

Physical Description
A circular brass cylinder on a thin steel plate mounted on a wooden board, screwed into a base wooden plate at three spots: the top and bottom two corners. Two brass nobs at the bottom front of the wooden plate can be loosened and tightened. These nobs have ribbed edges and are binding post terminals. It would appear that wires come out of the bottom of the cylinder through the wooden board and attached to the binding posts from the bottom. A lever at the left top of the brass cylinder rotates to start and stop. A small pin sticks slightly out of a small hole in the middle bottom of the base. The wooden plate also has small holes in each corner.

Funcitonal Description
It would appear that one winds up a spring inside using the square shaft/socket on the front like winding a clock (We did not attempt to work the machine, as it no longer has its key). The switch at the left then allows the spring to turn a rotor inside that spins inside a set of permanent magnets, which would create alternating current. Presumably, then, the Wheatstone bridge rectifier turns the AC into DC and the DC current could be tapped from the two binding post terminals on the front.

Creator

Timothy Maze, Liam Anderson, Zach Nicholas, Peter Amundsen; expanded by Steven A. Walton

Date

1890s-1910?

Language

English

Type

physical object

Identifier

C 108957. Also unidentified property tare reading 2900 and 12501, the latter on the plastic pressure tape (Dymo was one brand) that was popular from the 1970s-1980s

Coverage

United Kingdom

Physical Dimensions

[wooden base] 177mm width x 202mm width x 14mm height
[brass cylinder] 148mm diameter x 53mm height
[binding posts] 15mm diam., 20mm high

Materials

brass, copper, insulator, wood

Maker

Cambridge Scientific Instrument Co. Ltd., Cambridge, UK

Inscriptions

[top] Cambridge Scientific Instrument Co. Ltd., Cambridge, England | Stop Start | [diagram of Wheatstone Bridge] | C108957 | Made in England
[foil label on wooden base] Cambridge | Instrument Co.| Ossining, N.Y. | No.

Location

Fisher Hall, physics storage room

Social Bookmarking

Collection

Citation

Timothy Maze, Liam Anderson, Zach Nicholas, Peter Amundsen; expanded by Steven A. Walton, “Wheatstone Bridge,” Michigan Tech Inventory of Historic Scientific Instruments, accessed April 13, 2021, https://ihsi.omeka.net/items/show/199.