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Wheatstone Bridge An Overview. Orange Team Introduction to Engineering Design. Introduction. History How does it work? How is it used? Impact of the circuit Summary. : http://www.opamp-electronics.com/tutorials/bridge_circuits_1_08_10.htm. History.
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Wheatstone BridgeAn Overview Orange Team Introduction to Engineering Design
Introduction • History • How does it work? • How is it used? • Impact of the circuit • Summary : http://www.opamp-electronics.com/tutorials/bridge_circuits_1_08_10.htm
History • The Wheatstone Bridge was invented in 1833 by Samuel Hunter Christie • Later named after Sir Charles Wheatstone for his many applications of the circuit through the 1840s • The most common procedure for the bridge remains the testing of unknown electrical resistance
How Does it Work? • Uses ratio of 3 known resistors • Measures fourth unknown resistance • Balanced voltage between point 1 and battery’s negative, and between point 2 and battery’s negative allows the measurement : http://www.opamp-electronics.com/tutorials/bridge_circuits_1_08_10.htm
How Does it Work? (cont.) • By changing resistors to adjusting variable resistors to balance the device, the mathematical ratio is used to calculate the fourth (unknown) resistance : http://www.opamp-electronics.com/tutorials/bridge_circuits_1_08_10.htm
How is it used? • Main focus of the Wheatstone Bridge = applications using electricity • The circuit monitors sensor devices like strain gauges – it reads the level of the strain in the system • The galvanometer measures whether the gauges are balanced or not • Electrical power distributors use the Wheatstone Bridge to locate breaks in the power lines
Impact of the Wheatstone Bridge • The Wheatstone Bridge is a very simple design, although there are more complex versions of achieving the same outcome • Can be adjusted easily • Fairly inexpensive to produce • Also indirectly measures any variable that would change the resistance of a material • Ex: temperature, force, pressure
Summary • Created in 1833, popularized in 1840s • Wheatstone bridges are one of the best methods of measuring resistance due to the basic mathematical ratio involved. • Accurate standards with sensitive enough voltmeter, measurements of resistance within .05% can be reached. • Many calibration laboratories still use this method today. • The Wheatstone Bridge are replaceable; however, for its simplicity and versatility the circuit is an indispensible piece of technology
Works Cited • Johnson, R.. "MEMS enables electrically trimmable passive resistor. " Electronic Engineering Times 9 Mar. 2009: ABI/INFORM Trade & Industry, ProQuest. Web. 20 Sep. 2010. • Kuphaldt, Tony. "Bridge Circuits." OpAmp Electronics. Web. 19 Sept. 2010. <www.opamp-electronics.com/tutorials/bridge_circuits_1_08_10.htm >. • "The Wheatstone Bridge: Using Bridge Circuits to Provide Signal Conditioning."Suite101.com. Web. 20 Sept. 2010. <http://www.suite101.com/>. • "The Wheatstone Bridge. Web. 20 Sept. 2010. <http://www.play-hookey.com/>