Hi Everyone.
Please go easy. I'm an electronics noob with little experience. I'm good with programming, mostly in Python.
I've been messing with a 4.5hz natural frequency geophone and looking at ways to extend the bandwidth to 0.1hz at decent gain. I found a paper and got some help trying to design the circuit, built it, and it's somewhat working but I'm still not getting the response at very low frequencies.
Paper on extending natural frequency of 4.5hz geophone.
https://www.academia.edu/40257314/B..._5_Hz_geophone_for_seismic_monitoring_purpose
I don't fully understand the circuit. The first part is just a preamp? I built it using 2 10k resistors and an LM358 opamp.
For the second part, I set the gain to 30 (1 + R4/R3), 10K for R3 and 290K for R4. I used a 0.1uF cap to set the bandwidth. Also with an LM358.
I'm feeding +5 and -5v into the system for the opamps, the signal goes to a 16bit ADC with ability to increase gain there.
I've attached the specs on the geophone.
All in all, this is really above my head. I know enough to mess around and build a test circuit, but a lot of the theory and approach is beyond me.
If some expert on opamps and bandwidth extension could help me figure out a circuit to extend the bandwidth on this geophone, I'd be eternally grateful.
Please go easy. I'm an electronics noob with little experience. I'm good with programming, mostly in Python.
I've been messing with a 4.5hz natural frequency geophone and looking at ways to extend the bandwidth to 0.1hz at decent gain. I found a paper and got some help trying to design the circuit, built it, and it's somewhat working but I'm still not getting the response at very low frequencies.
Paper on extending natural frequency of 4.5hz geophone.
https://www.academia.edu/40257314/B..._5_Hz_geophone_for_seismic_monitoring_purpose
I don't fully understand the circuit. The first part is just a preamp? I built it using 2 10k resistors and an LM358 opamp.
For the second part, I set the gain to 30 (1 + R4/R3), 10K for R3 and 290K for R4. I used a 0.1uF cap to set the bandwidth. Also with an LM358.
I'm feeding +5 and -5v into the system for the opamps, the signal goes to a 16bit ADC with ability to increase gain there.
I've attached the specs on the geophone.
All in all, this is really above my head. I know enough to mess around and build a test circuit, but a lot of the theory and approach is beyond me.
If some expert on opamps and bandwidth extension could help me figure out a circuit to extend the bandwidth on this geophone, I'd be eternally grateful.
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