Search results
Results from the WOW.Com Content Network
A Wheatstone bridge is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. The primary benefit of the circuit is its ability to provide extremely accurate measurements (in contrast with something like a simple voltage divider ). [ 1 ]
The best-known bridge circuit, the Wheatstone bridge, was invented by Samuel Hunter Christie and popularized by Charles Wheatstone, and is used for measuring resistance. It is constructed from four resistors, two of known values R 1 and R 3 (see diagram), one whose resistance is to be determined R x , and one which is variable and calibrated R 2 .
Voltage dividers are used for adjusting the level of a signal, for bias of active devices in amplifiers, and for measurement of voltages. A Wheatstone bridge and a multimeter both include voltage dividers. A potentiometer is used as a variable voltage divider in the volume control of many radios.
The two remaining arms are the nearly equal resistances P and Q, connected in the inner gaps of the bridge. A standard Wheatstone bridge for comparison. Points A, B, C and D in both circuit diagrams correspond. X and Y correspond to R 1 and R 2, P and Q correspond to R 3 and R X. Note that with the Carey Foster bridge, we are measuring R 1 ...
The suggested setting for the configuration shown, is with R1 = R2, and R3 around the middle of the range of the RTD. Looking at the Wheatstone bridge circuit shown, the voltage drop on the lower left hand side is V_rtd + V_lead, and on the lower righthand side is V_R3 + V_lead, therefore the bridge voltage (V_b) is the difference, V_rtd − V ...
However, the method went unrecognised until 1843, when Charles Wheatstone proposed it, in another paper [3] for the Royal Society, for measuring resistance in electrical circuits. Although Wheatstone presented it as Christie's invention, it is his name, rather than Christie's, that is now associated with the device.
A Maxwell-Wien bridge. A Maxwell bridge is a modification to a Wheatstone bridge used to measure an unknown inductance (usually of low Q value) in terms of calibrated resistance and inductance or resistance and capacitance. [1] When the calibrated components are a parallel resistor and capacitor, the bridge is known as a Maxwell bridge.
The operation of the Kelvin bridge is very similar to the Wheatstone bridge, but uses two additional resistors. Resistors R 1 and R 2 are connected to the outside potential terminals of the four terminal known or standard resistor R s and the unknown resistor R x (identified as P 1 and P′ 1 in the diagram).