Resistive sensor (20 Points to grab)

[viks]

Hi guys,

I need to use 0-200 Ohms pressure sensor in my project.

I am facing problem with linearity of circuit.
Can anyone suggest how can I get better linear response from my circuit.

Thanks

 

[yxo]

Perhaps, try make lower sensitivity of sesnsor and use amplifier with gain more then one. The very simple is set parallel resistor to R3

 

[surianova]

Hi guys,

I need to use 0-200 Ohms pressure sensor in my project.

I am facing problem with linearity of circuit.
Can anyone suggest how can I get better linear response from my circuit.

Thanks

what i see from the resistor, is not a linear function by itself.

vout= R3/(R1 + R3)X V1 , with R3 and vout as variable.


you can change to non-inverting configuration.

vout= vin(1+R1/R3) , when R3 change, vout change linearly.

 

[safwatonline]

well, u can use the resistor in differentiator configuration so that the Vout=RC*dVin/dt then u can apply a dummy stimulus signal Vin this wil modulate ur signal (represent inherent chopping stabilization) so at the output u will have to demodulate ur signal back using the same Vin.
Vout/R=C*dVin/dt so if Vin=A*coswt >>
Vout/R=C*A*w*sinwt by multiplying with A*sinwt
Vout/R=[(C*w*A^2)/2]-(C*w*A^2)/2*cos2wt
LPF: Vout/R=(C*w*A^2)/2
which is linear, seems much more complex

BTW surianova the signal here is R3, so we need to have a linear Vout/R3

Added after 2 minutes:

BTW i considered R proportional to the pressure, is that right?

 

[ravimarcus]

I need to use 0-200 Ohms pressure sensor in my project.

I am facing problem with linearity of circuit.
Can anyone suggest how can I get better linear response from my circuit.

Try constant current source like you would do for RTD's using LM317 or LM34.

Cheers

Ravi