Re: Op Amp - Design question

Well, with taking the output of the envelope detector and passing that
to a difference amp as described in my OP, I am amping ~150 times
bringing the output of my amp to ~3-4 volts. It isn't very noisy and I
am able to sample and get the resolution I need. The sensor is
actually
functioning perfectly. My only issue is in pratice, I won't have a
$4000 programmable PS available to null out the DC component at the
difference amplifier.

Being a digital guy, what I was thinking was to take the steady state
out of the envelope detector, passing it through a A/D, and storing it
a small micro. Then I could use a SW programmable pot or similar to
"null" the effect of the DC component into the difference amp. This
approach will work, but I figured I would investigate an analog
equivelent that would be cheaper as well as take up less real estate.

Dave

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