Instrumentation amplifier - Problem of noise with load cell and - You ought to have a skip capacitor across the energy enter (100uf/10v in parallel with 0.1uf ceramic will do), 10n enter caps on every enter line, as andy shows, with collection resistors, and i'd also recommend a 10n capacitor from reference output to floor.
My trouble: when i'm in sure places, wherein likely there is a lot of parasitics, the sign from the ina125p varies approximately five while my hand is near the load mobile, but now not touching it! It handiest happens at a few places but now not others. As an example, at domestic, there is no hassle; the signal may be very solid. Additionally, the amplitude of the noise appears to be proportional to the gain of the amplifier.
Update 6/05 : to be extra precise about the version, here are some examples: - while the weight mobile lays on a table, no forces on it, the signal (after adc) is 440 (the cost are from 0 to 1024). If i method my hand close to the cell with out touching it, the sign drops to 425 and if i touch it, it drops a touch bit more to approximately four hundred. - While i have the burden mobile in my hand, and that i lift my arm up of about 20 inches, the sign is going as much as 460, after i come back to the table, the sign returns lower back to its preliminary value.
Because of technical constraints, i need to apply a 9v battery to power the whole system. Additionally, desiring to measure the pressure in each directions, i want the signal that comes out of the ina125p tp be referenced to 2.5v about. Here is the real schematic:.