Wheatstone bridge
A Wheatstone bridge is a circuit that is used to measure an unknown resistance. This is done by balancing two legs of a bridge circuit. One of which includes the unknown resistance. The Wheat stone consists of four resistors connected as a square. The circuit is balanced when R 2 /R 1 = R x /R 3 . The current will be zero in this case. If the circuit is not balanced, a current will flow and can then be measured.
Formulas
When the Wheatstone bridge is balanced, The unknown resistance can be calculated with one of the following formulas:
The output voltage can be calculated with the following formula if all resistances and the input voltage are known:
R is the symbol for resistance and is measured in ohm (Ω).
V is the symbol for voltage and is measured in volt (V).
V out is the output voltage and is measured in volt (V)
Calculators
Resistance
You can use this calculator to calculate an unknown resistance.
Output voltage
You can use this calculator to calculate the output voltage by entering all resistances and the input voltage.