bridge (electrical measurement). Article #4. Vol. 2, pg 513.
When learning something new, we’d ideally start from first principles and build on what we already know to learn more advanced topics. The problem with hopping around Britannica randomly is that I’m going to stumble onto topics for which I’m completely unprepared.
That’s the case when it comes to trying to understand a bridge circuit. I never took any courses in electronics or circuit design, though the whole V = IR thing sticks in my head for some reason.
The idea of a bridge circuit is that you can use the known values of three resistors to calculate the resistance of a fourth.
When no current is running between nodes 1 and 2, the ratio shown holds true. So if you know Ra, R1 and R2, you can figure out Rx using basic algebra.
“bridge (electrical measurement).” Encyclopedia Britannica. 15th ed. 2010. Vol. 2 pg 513.
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