Your right the snubber did not work. I put a 470 uf 100V LYT cap on the 12V rail and found that the spikes were reduced greatly, but still have spikes up to 19V and down to 9 volt with an unloaded motor. Not sure what the inductance is, here is the motor though...
Can you see the photo now? Not sure what's going on.http://files.engineering.com/getfile.aspx?folder=bdf9b4a9-8be9-49d9-af69-0aab96a50ce6&file=CIMG5348.JPG
Here is the picture of the spikes.
Do you think a snubber on the motor terminals would do the trick?
JLhttp://files.engineering.com/getfile.aspx?folder=49e04929-8d7d-421e-9b54-3788adae564b&file=CIMG5348.JPG
I have a 12VDC circuit that uses an Atmel 8535 to drive two DC motors @ 14Khz PWM locked anti-phase. I have blown a couple of my on board 5VDC regulators and when I put a scope on the 12VDC power within the board it was very choppy. The voltage spikes seems to go over 50V until I put a 0.1 uf...