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Wheatstone bridge

DC circuits · Beginner · about 10 minutes · part of Zen’s Electronics Design Mastery

Two dividers side by side. When R1/R3 = R2/Rx the midpoints sit at the same voltage and the meter between them reads zero. That null finds Rx.

Wheatstone bridge: the circuit on the simulator's bench

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How it works

VA = Vs · R3 / (R1 + R3), VB = Vs · Rx / (R2 + Rx)

VG = VA − VB = -745.6 mV with R3 at 3 kΩ

Balance (VG = 0) when R3 = R1 · Rx / R2 = 4.7 kΩ. Then Rx = R2 · R3 / R1.

Try it on the bench

  1. Scroll over the pot (R3) until V_G reads 0.000 V. Read Rx off the last row.
  2. Change Rx to another value and balance it again.

Parts on the bench

In the course

Zen’s Electronics Design Mastery, module “DC Circuit Analysis”.

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