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Changing FOC Switching frequency

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#61

I just measured (with the vesc) each of the motors in the setup, and the two i posted plots for yesterday.
The more efficient of the two (HobbyWing x-rotor 8120-100kv) is at 6.27uH
The less efficient, (Turnigy 9235-100KV Multistar ) is at 11.14uH.

I’m going to set up the scope in a second and see what i can see.


#62

@Petertaylor do you think the “more efficient” motor has lower inductance from having less iron/stator volume and therefore more room for copper… lower resistance & lower inductance… more efficiency?


#63

good question.
I’m absolutely no expert on this stuff (read on), so i really couldn’t tell. I’d like to know, but i’m not there yet :-/

Also, guess who just fried their usb o-scope? Yep, forgot that while i could drill-scope motors at low rpms and get low induced voltages, the Digilent AD2 only has a max voltage of 26v. The difference between phases on the motor was at ~50v at its peak. Looks like just one SMD component next to the usb port, but you never know. I’ll use this as an excuse to get a real scope…

So, the scope trace will have to wait until i get a real scope (few days? a week?)