Guru
Joined: 26/07/2007
Location: AustraliaPosts: 1686
| Posted: 08:28am 11 Mar 2017 |
Poida,
Thats exactly what I am talking about.... no noise in transition, even at very high power levels, but can get noise at steady state operation... weird..... It takes a few seconds at steady state for the noise to arrive.
Maybe you can program for minor movements in the pwm pulse to keep the noise and wiggle out, but not materially affect the voltage.... ie two step forward and one step back, and then two back and one forward for steady state... i have no idea really..... as we are changing the pulse width all the time already to make the wave in the first place... so whats different when we change load or voltage?
Unless there is some asymmetry when we are moving to more power or higher voltage in the waveform we can't really see, but enough to stop the resonance.... maybe we need to not have a mirror image in the quadrants, but a slightly asymmetrical sine wave??
.....oztules
Village idiot...or... just another hack out of his depth