## Saturday, November 13, 2010

### Wheatstone Bridge

http://en.wikipedia.org/wiki/Wheatstone_bridge

Wheatstone bridge is an electrical circuit invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843. [1] It is used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. Its operation is similar to the original potentiometer.

The desired value of Rx is now known to be given as:
$R_x = {{R_3 \cdot R_2}\over{R_1}}$