ORIGINAL: Dean Pappas
Hello Jim,
Is that ripple at commutation rate or at the chopping rate? Sorry I couldn't read the timebase.
400 mV on two cells! I guess it's not that surprising. So that works out to maybe 2V peak to peak across the entire pack.
Sounds like more filtering at the ESC would lessen the current peaks at the battery. I wonder if the batteries will respond well to that.
Regards,
Dean Pappas
The timebase was .2 msec per division so it looks like it is the 8KHz PWM frequency. I never went to full throttle but I would assume the ripple would disappear at 100% duty cycle as you would get a fairly pure DC at that point. I don't know what the effective series resistance is across the two cells but the 400 millivolts seems reasonable if the R was 10 milliohms and the I was 40 Amps.
We need the regulator to get down to 6 volts and it does the filtering so I don't see a need to do anything else at the battery/ ESC interface.
What have you been up to? What ever happened to electric control line? I can't keep up with all the stuff that is going on but I find a lot of folks getting ahead of the pattern guys when it comes to new technology.
Regards, Jim