Amplifier for dynamic strain guage

[nm2007k]

Hi ,
I want to make an amplifier to amplify the load cell output of 2mV/V(Excitation voltage) to Voltage of range 0 to 10 V

The key point is my load will vary from 1 Hz to 1 KHz. so how to amplify this a.c signal without noise.

My loadcell bridge resistance is 350 ohm.

I ve one amplifier but the problem with that is, it is having an LPF for noise reduction that makes my output to reduce when the frequency increases.

Thanks in advance.

 

[chuckey]

If you remove the LPF, how much noise is there?. What you are after is a typical hi - fi preamplifier.
Frank

 

[KlausST]

Hi,

I recommend to use a two stage amplification.
2mV to 10V needs a gain of 5000. With 1kHz bandwith you need a gbw of 5MHz and some overhead...

So with two stages you need a gain of about 70. Use low offset, low offset drift opamps. Maybe chopper stabilized.
Also add high order lowpass filter to avoid amplifying the noise.

If proper layout and take care of thermocouple effects...

If you are not satisfied with this then you need more effort and supply the sensor with an AC signal.
Extra circuitry to demodulate sensor output.

Klaus