Hi Folks,   We have  been working on a simply cheap, seismic sensor 
amplifier.  Just an op amp and a few components.

We seem to have it working, and so far so good, We are using the Arduino.

Now we need to decide, what gain it should be.   There maybe no one answers. 
On professional amplifiers, like Larry's board, there are several gains 
avail via the pot and jumper.

This will be fixed resistor, so for now I will limit my question to this.
Q.  Is there a down side to too much gain, is there some sort of trade off, 
if you use a large gain, say 2000, do you give up something, like drift, or 
clipping etc.

I know very little about op amps and these values.   The coil in question is 
approx. 970 ohms.

I have tested it with op amp gains of approx.  60, 80, 100, 150, 220, 470 
and even 1000.   I could pick any of these gain, as they all seem to work, 
and leave it at that.  I have a nice coil and magnet arrangement, so I don't 
need a lot of gain.

Thanks, Ted 

__________________________________________________________

Public Seismic Network Mailing List (PSNLIST)

To leave this list email PSNLIST-REQUEST@.............. with 
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.