Hey all,
let me first say hello, as a newcomer on the forum! Good to be along electronic specialists.
I have a (perhaps trivial) question that is buzzing me a bit these days. A brief explanation of the project: I have metallic plate with two piezoelectric sensors attached on each side. One is used as transmitter (TX), other as receiver (RX). I am driving TX with function generator and high voltage amplifier. On RX I am trying to measure the output (see the waveform).
Now, problem is the following: When I am measuring with oscilloscope, it picks up the noise from the power supply, which is generated by the amplifier (noise is exactly the same shape as input signal into TX piezo). I have tried using power transformer to get rid of the dirty ground, but it doesn't change a thing. I know I have to create some 'buffer circuit' between RX and oscilloscope and have some ideas, but would also appreciate your ideas/suggestions, not to spend too much time on this problem.
Here's the circuit I have thought of:
INA stands for instrumentation amplifier (classic schematic with three op-amps), lower part is an averager. I would measure with oscilloscope between the two output on the schematic.
Any ideas/thoughts are welcome.
Thank you and best regards,
Blaz
let me first say hello, as a newcomer on the forum! Good to be along electronic specialists.
I have a (perhaps trivial) question that is buzzing me a bit these days. A brief explanation of the project: I have metallic plate with two piezoelectric sensors attached on each side. One is used as transmitter (TX), other as receiver (RX). I am driving TX with function generator and high voltage amplifier. On RX I am trying to measure the output (see the waveform).
Now, problem is the following: When I am measuring with oscilloscope, it picks up the noise from the power supply, which is generated by the amplifier (noise is exactly the same shape as input signal into TX piezo). I have tried using power transformer to get rid of the dirty ground, but it doesn't change a thing. I know I have to create some 'buffer circuit' between RX and oscilloscope and have some ideas, but would also appreciate your ideas/suggestions, not to spend too much time on this problem.
Here's the circuit I have thought of:
INA stands for instrumentation amplifier (classic schematic with three op-amps), lower part is an averager. I would measure with oscilloscope between the two output on the schematic.
Any ideas/thoughts are welcome.
Thank you and best regards,
Blaz