Hi All,

I have built the attached sensor amplifier which works well.
It outputs to a dvm to give a 0 - 10v reading.

The last two stages U1b and U1c are described as a 2 stage 10hz low pass filter to remove noise from the earlier stages.

What I would like to know is, would this design suffer by any significant margin if I removed the last stage U1c.

I get the feeling the designer may have just used U1c up such , rather than leaving it unused.

My reason for wanting to do so, is that I can then build two amps, with just one quad TL084 chip.


thanks

Richard

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The last op-amp provides a voltage follower type buffer.
Whether you can miss it out all depends on what is connected to the output of the filter.
If it is a nice high impedance circuit, it is probably OK to lose the last opamp stage.
However, if what is connected to the output loads it in any way, the filter characteristic will be affected.

For "good practise" I would leave the buffer stage in.

JimB

__________________
Experience is directly proportional to the value of the equipment ruined.

 

If your multimeter has a 10Megohm input resistance, as most do, then your error will be approximately 1% (10/10.1 ~ .99).

__________________
Ron