Inverter building using Wiseguys Power board and the Nano drive board

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wiseguy Guru Joined: 21/06/2018 Location: Australia Posts: 1206	Posted: 09:53am 07 May 2025         KeepIS said   A VERY quick Look at Induced buzz: Put a 1uf across the AC output and the spark does the same thing, it stops the buzz. Place a microphone near the toroid, if it hears a buzz, close a relay that applies a momentary capacitor across the secondary lol   I would have expected the momentary capacitor would have a 50% chance of curing or continuing the buzz. Is it a resonance issue with the main components (culprits) being transformer choke and output capacitance and adding the other capacitance reduces the Q (detunes it) back to the edge of stability? I have not experienced this issue exactly as described. When my Toroid has a buzz or hum episode it drifts in and out at random but it never stays for any length. Fascinating that a momentary capacitor connection will "fix" it. Maybe in software at idle we could employ an MPPT - minimum power point tracking that can toggle (suppress) one or two of the narrowest SPWM bits on the appropriate half sine to keep the core magnetics balanced near to the mid point.  Maybe the noise - which does not appear to do anything bad - and only occurs at no/low loads should just be ignored? We might kill the patient whilst trying to cure it. Edited 2025-05-08 08:47 by wiseguy