Hi there,
I am having a problem with my circuit.I am using the INA125 amplifier. I am using a single supply voltage about 12 v and using the voltage regulator to give me 5v on to a quarter bridge. I have been using a 10 ohm/25turn potentiometer as my strain gauge plus 340 fixed resistor. I have been checking that for each turn on the strain gauge the voltage should change in a certain amount.but my results are half off.
calculation =((4.98*0.4*#of turns)/(2*(2*365+0.4*# of turns)))
results after each turn starting from 0
trial 1 trial 2 actual amount calculated
0 0 0
0.437 0.492 1.36006
1.2 1.226 2.718632
2.08 2.091 4.086433
2.57 2.62 5.445599
3.35 3.41 6.803279
4.05 4.13 8.159476
4.73 4.79 9.519476
5.32 5.35 10.86743
I set each potentiometer to 25 each so that r1 to r3 is 365 while the r4 is 370. I balance the circuit and then I turn the 10 ohm potentiometer set as 5.I am using 1000 gain. I am not using a load between 11 and 5 only because the voltmeter it self has resistance
I am having a problem with my circuit.I am using the INA125 amplifier. I am using a single supply voltage about 12 v and using the voltage regulator to give me 5v on to a quarter bridge. I have been using a 10 ohm/25turn potentiometer as my strain gauge plus 340 fixed resistor. I have been checking that for each turn on the strain gauge the voltage should change in a certain amount.but my results are half off.
calculation =((4.98*0.4*#of turns)/(2*(2*365+0.4*# of turns)))
results after each turn starting from 0
trial 1 trial 2 actual amount calculated
0 0 0
0.437 0.492 1.36006
1.2 1.226 2.718632
2.08 2.091 4.086433
2.57 2.62 5.445599
3.35 3.41 6.803279
4.05 4.13 8.159476
4.73 4.79 9.519476
5.32 5.35 10.86743
I set each potentiometer to 25 each so that r1 to r3 is 365 while the r4 is 370. I balance the circuit and then I turn the 10 ohm potentiometer set as 5.I am using 1000 gain. I am not using a load between 11 and 5 only because the voltmeter it self has resistance
