Since one of the sensors in my project requires amplification, I've been spending a substantial amount of time getting down and dirty with various OpAmps in an effort to find one ( ... and a particular configuration) that meets all my criteria.
Most importantly, the sensor needs to be amplified enough to present a consistent and wide range of load measurement while not drawing/requiring too much power.
OpAmps generally allow for either "dual" or "single" supply configurations meaning that they require either one or two power supplies in order to operate.
By power supplies, I mean power sources which, in the case of my project, ultimately means batteries... and for this project I would like to keep both the overall power draw and number of replaceable or rechargeable batteries to an absolute minimum.
You would think this decision would be simple... just go with the "single" supply configuration and an OpAmp that can operate with a very low voltage.... but it's not quite that easy as there are many trade-offs and nuances.
First, generally speaking... ( ... remember this is all essentially new to me) "single" supply amps can deliver the similar dynamic range of amplification as the "dual" configuration but with the requirement of a higher single voltage.
For example, a "single" source amp might be able to take a single 5V supply and amplify the source signal within a range of 0 - 3V while a dual configuration might take two 2V supplies to create a range between -1.5V and +1.5V ... also a 3V total range.
Further... there is a the possibility of choosing an amp that supports "rail-to-rail" operation which allows either a "single" or "dual" configuration to generate an output voltage very near the input voltage which appears to me to be essential in a low power application.
Ultimately though, the configuration has to work for the application so the first order of business is test both the "single" supply and the "dual" supply configurations with the sensor across a range of voltages in order to establish the minimum voltage needed to make accurate ( ... and distinguishable) measurements across the desired range loads.
My wishful hope at this point is that I can make accurate measurements with an amplified single that ranges from 0V ( ... no load) to 1V ( ... many hundreds of pounds of load)... but I wont really know for sure until I capture and plot the output data.
Currently, I have the sensor in a "dual" configuration with two 1.5V supplies ( ... a tad under the recommended lower bound of voltage for this amp) and it appears to function pretty well but the proof has yet to be established so stay tuned!
Best to all...
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