[sdiy] Op amp clips prematurely?

[Ove Ridé]

On 3 February 2014 04:40,  <nvawter at media.mit.edu> wrote:
> A few people have suggested using a series resistor and gain amplifier to
> overcome the range issue.  I believe that would solve the issue, however, it
> seems it might also create an issue of having to trim every one of these
> sensors.  Therefore, I ~think~ I'd like to try using a different device
> instead, one that's input swings from rail to rail.  I did some sifting on
> DigiKey and found an inexpensive part, the MCP6002 (1).

Don't give up yet! Instead of putting a resistor in series, generate
Vcc/2 and use that as your reference for the pot. Use a dual opamp.
Use one opamp connected as a voltage follower to a Vcc/2 voltage
divider, as a buffer. Connect the previous Vcc terminal of the pot
there. And then connect the pot's "wiper" to the *2 amplifier like
before.

-- 
/Ove

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