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Voltage regulation issues

  1. Aug 8, 2011 #1


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    Edit: It turned out that the battery died. However, if anyone knows a better way of doing what I'm trying to do, I'm all ears!

    Hi everyone,

    I'm trying to amplify the derivative of a signal around 30mV, that would change by a few microvolts per second using several instrumentation amplifiers (INA102). I had some success doing this using two 9-volt batteries. However, I would like to use a single 9V battery as my supply.

    Originally I used an LM317 voltage regulator to produce 5.6V, and then two 100Kohm resistors as a voltage divider. 2.8V would be a virtual ground, so my amps would see +/-2.8V. However, this did not work while connected to the circuit, probably because it was unbalanced.

    Right now, I've set up two LM317 voltage regulators, one at around 2.8V and the other around 5.6V. [STRIKE]However, these voltages drop when they're connected to the circuit too. Maybe I can't use voltage regulators like this? [/STRIKE] Thanks in advance for your thoughts!


    signal(~30mV)--INA102(amplification of 100)--INA102 differentiator(amplification of ~1000)--INA102(amplification of 1000)---output
    Last edited: Aug 8, 2011
  2. jcsd
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