What will happen if you use the geophone between the negative
inputs in an Instrumentation amplifier comprised of three
typical op-amps ?

OR

in some kind of Push Pull (Class "B") configuration with both geophone leads
attached somehow to two opposing operational amplifiers ?

Since the spice simulator will not simulate physics things other than electronics,
I can not experiment with geophones using the software, I now have.

It seems a person really needs a more complete simulator
to look at and test the real physical world.

-----Original Message----- 
From: Christopher Chapman
Sent: Monday, May 09, 2011 10:09 AM
To: psnlist@..............
Subject: Re: NEVADA EVENT ??? M2.7 ??? seen in Apache Junction ??



Subject: Re: NEVADA EVENT ??? M2.7 ??? seen in Apache Junction ??


It is odd but I am unable to get a flat velocity response cheaply.  I guess my waveform is displacement below 1 Hz and Acceleration 
Above 1Hz, Only right at 1Hz might you call it velocity.  What kind of seismometer is that ? Hi Geoff, If you put your 1 Hz geophone 
onto a high impedance non inverting amplifier input, you get a velocity response above the resonant frequency. You then increase the 
damping to ~critical by loading the geophone with a damping resistor. This is necessary to flatten out the high frequency response. 
Regards,Chris Chapman 

__________________________________________________________

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.