Well it's low level but definitely present and yes, this is rat nest breadboard action, so I'm not expecting silence. The "forever in dev" charger, of course, is of which I speak... haha
Earlier I saw the noise floor competing heavily with the shift in each step on the high side sense line to ground, so it's pretty smooth and quiet considering.
This one was taken from the master Vfb output headed for the KA7500 [TL494].
Time 5uS, 20mV/Div, Signal ground ref, AC mode.
Not taken at full throttle; CV mode running about 15A or so into 13.5V as I recall on this one (38% of theoretical, 47% of limited max output).
Tube memory was used, and scope isolated on dedicated battery.
Amplitude of spikes increases proportionally and in the same pattern as drive/output goes up... They remain the same otherwise. Exact source unclear at the moment, it's pretty prominent throughout as a common mode leak, probably in the grunt, but there's no noticeable shift in PWM duty component... As such, pretty "invasive"
It'll be nice if that calms down a bit more after final assembly nears closer, as I think it's what's introducing a little bit of twitch in the amps, which of course causes the PID to react. Not obnoxious, but there at times. Hysteresis doesn't do too bad a job of handling it; window is about the same on the output voltage control; about 30mV keeps it in check for the moment.
It's possible the spikes are the hard CC foldback transistor catching (and suppressing) these needles at the master battery bus, as the one place they seem a bit more toned down is at the Vsense lead, but again, where's the PWM modulation?
They're not a real big deal as things sit but of course the OCD in me wants them gone. That said, overall I'm happy so far, it's been slow, but all the extra "hmm" is starting to show sneak peeks of the rewards. Hopefully soon I'll have it fully laid out on vero and can turn everything over to code. These are sweet little boards, and once you've beaten the language and compiler into submission, they start to pull rabbits out of hats
Stay tuned lol
