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@ericfont

ericfont/circuit-20251130-2020.svg

Created December 1, 2025 01:19
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something working, with hystersis for comparator and summing input with feedback
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ericfont commented Dec 1, 2025

so to decimate the delta PWM signal, apply that formula y[n]=x[n]-x[n-1]+a*y[n-1] and continuously accumulate that, and dump every nysquist sampling rate sum as the delta for that nyquist sample. If can get the oscillation to be around 96kHz, then a simple boxcar averager will null that oscillation when downsampling to 48kHz.

Also note during analog reconstruction, a simple notch filter will null around that oscillation.

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ericfont commented Dec 1, 2025

hypothetical notch filter:

image

Might want to combine notch with general lowpass and maybe notch higher overtones too.

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ericfont commented Dec 1, 2025

image

nice no jaggedy integration

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