Apr 1, 2019
Charles Wheat – Scientist of the Day
Charles Wheat, an American physicist, chemist, and civil engineer, was born Apr. 1, 1761.
read more...
seen from Netherlands
seen from Nicaragua
seen from Canada
seen from United States
seen from Spain
seen from Türkiye
seen from Canada
seen from Türkiye
seen from United States
seen from Malaysia
seen from Australia
seen from Yemen
seen from Canada
seen from United States
seen from China
seen from United States
seen from Spain
seen from Russia
seen from United States
seen from United States
Charles Wheat – Scientist of the Day
Charles Wheat, an American physicist, chemist, and civil engineer, was born Apr. 1, 1761.
read more...
commission first draft (2016)
Wheatstone Bridge
- made up of 4 resistors in a square with a sensor as one of the resistors - change in resistance of Rsensor gives change in Vo - Vo=Va-Vb, where a and b are points between R1/2 and R3/4 - Va=I1*R4=(Vs/(R1+R4)) *R4 - Vb = I2*R3=(Vs/(R2+R3))*R3 - Vo=[(R4/(R1+R4))-(R3/(R2+R3))] = (R4*R2-R3*R1)/((R1+R4)(R2+R3)) - Vo= 0 when R4*R2=R2+R3 - R1/R4 = R2/R3 - if R1 was a strain gauge, R1 becomes R1+ΔR - if R»ΔR, Vo~=(ΔR/4R)Vs - the sensitivity k= Vo/ΔR = (Vs/4)(1/R) - the sensitivity of the system increases by the factor of number of sensors added - output and input is always linear - sometimes sensors are far from the rest of the circuit, and resistance of cables add resistance to the sensor - this is compensated by using long leads of equal length for that entire half of the bridge, so the resistive differences compensate themselves -
Wheatstone bridge
circuit which has 4 resistors connected in a square with 1 of unknown value, with a measurement device in the middle.
works well as a control system.