boylesg
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Can anyone tell me if this is a correct principal for noise cancellation.
In this case it is not for listening to music or what ever, rather to reduce bank ground noise for sleeping purposes.
So I am assuming I would not need a summing amplifier stage.
1) Speaker over ear with electret microphone on the back
2) AC coupled inverting amplifier to generate the inverted anti noise signal come in from the microphone.
3) Adjustable delay circuit to get simultaneous noise and antinoise in the ear.
4) Adjustable antinoise volume.
I could possibly use an ESP32 microcontroller to implement an adjustable delay, because it has both ADC pins and DAC pins.
But is there a simpler circuit of adjustable analog signal delay?
In this case it is not for listening to music or what ever, rather to reduce bank ground noise for sleeping purposes.
So I am assuming I would not need a summing amplifier stage.
1) Speaker over ear with electret microphone on the back
2) AC coupled inverting amplifier to generate the inverted anti noise signal come in from the microphone.
3) Adjustable delay circuit to get simultaneous noise and antinoise in the ear.
4) Adjustable antinoise volume.
I could possibly use an ESP32 microcontroller to implement an adjustable delay, because it has both ADC pins and DAC pins.
But is there a simpler circuit of adjustable analog signal delay?