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I need to measure force with a load cell and transmit it to a computer.

The load cell outputs 2mV/V for whole range. Vdd < 12V, so I have 0..24mV signal, which I assume is enough to have good resolution and probably good signal/noise ratio.

The Manufacturer also produces amplifiers for these cells, which are pricy (cost as much as the cell itself), bulky and have extra features (like galvanic isolation), do I realy need them?

Is it a good idea to cut expenses using custom designed amplifier from standard instrumental amplifier (for example AD620) or put signal straight to adc (for example AD7705).

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  • \$\begingroup\$ Did you ever try the AD7705? It seems to be the perfect part for what I want to do but it's good to read other people's experience. \$\endgroup\$
    – Edgar
    Feb 13 '20 at 11:54
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  1. If you have an ADC that gives sufficient resolution (which is a measure that you have to decide on/give us, we can't answer that for you) using only your 0-24mV signal, then this is likely the best option.

  2. The amplifiers which are made by the same manufacturer are likely to work well with their transducer & the isolation sure shouldn't hurt anything.

  3. You could magnify the output voltage using something as simple as an OpAmp voltage multiplier circuit like this one:
    enter image description here
    (Note that this circuit DOES NOT isolate your ADC from the 24V supply, should the op amp or transducer fail)

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