Flipsky 75200 struggle/cogging on higher voltage >>> Solution

what happend?

The gates of the 7769 Mosfets are driven too hard / Gate resistors too small (maybe just a design issue (hard switching = distortion)

On prevous 75200 (until 2021) the six Gate Resistors are 1.6 ohm ( SMD 0603)

Later they change them to 4.7 ohm .

BUT ,
if the input voltage is higher than 30V there are massive Problems with cogging / stuttering / Motor screaming.

When the voltage gets over 45V it ist just unusable.

SOLUTION:

Change the six Gate resistors to 16 - 22 ohm (all of them must be the same )
Change the Dead time in the Firmware (16ohm ~ 1450ns) (22ohm ~ 1650ns)
(this point is tricky ----better check with Oscilloscope )

At least change the switching frequency to 13 - 16 KHZ to reduce switching losses

Test @ 185A with Flipsky 80100 Motor on 16S ....worked like a charm

Disadvantages of this solution :

Lower efficiency ,much more heat on the 75200, some noise from the lower frequency