On 07/01/2022 02:39, Jon Elson via cctalk wrote: > Yes, the 2nd unit is running at 5 KHz, clearly explaining the noise. > Possibly there is a bad flyback diode, or something causing the > different waveform. >
That would be D5 I guess? I did do some checks in this area but I can't remember if I swapped that particular part with the other unit. I did a DC test out of circuit using the bench supply and it seemed to work with no leakage in the reverse direction. Perhaps it only fails when running at full speed? Regards, Matt