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Electronics => Electronics => Topic started by: sparky_joe on June 02, 2012, 01:44:26 PM

Title: amplifying accelerometer output
Post by: sparky_joe on June 02, 2012, 01:44:26 PM
I want to amplify the output from my accelerometer
 so that small changes in output voltage from the
 1.6V "static" state would be amplified. So, for example,
 if the voltage increases to 1.8 (delta=+.2V)
because of a small acceleration, I would amplify that
 voltage change by a gain of say, 5, so that this same
 acceleration would result in an output voltage of
 2.6 (.2 X 5 = 1.0, 1.6 + 1.0 = 2.6).  This output
would be fed into my Arduino Analog input so that I
can detect very small accelerations. Does anyone know
how to make an op-amp circuit that will accomplish this?
Title: Re: amplifying accelerometer output
Post by: ahudak on June 05, 2012, 03:23:07 PM
Hi,

The gain of a opamp is the ratio between the input resistor ( R165 ) and the feedback resistor ( R195 ).  The amp in the pic has a gain of 1 as the resistors are the same value.  If R195 was made 30K the gain would be close to 3, only in a perfect world will it be exactly 3 as there will be stray interference from the layout and the parts themselves.

Hope this helps
Art