Motor braking.

[BrianG]

OK, thanks! That makes sense. I guess I just didn't understand the statement:

Originally Posted by GriffinRU

If controller doesn't open FET's then BackEMF from motor will be rectified by built-in diodes and will be charging battery, if battery voltage will be less then backEMF+voltage drop. You can optimize this process if you open FETs in sync with diodes, then you will cut off diodes voltage drop and losses.
If you noticed braking can be done with only one side, while recuperating involved both.

My confusion stems from the diode aspect. I know the diode is built into the FETs. So, if the FET simply shorts the phases, how can you eliminate the v drop of the diodes?

[GriffinRU]

Originally Posted by BrianG

OK, thanks! That makes sense. I guess I just didn't understand the statement:



My confusion stems from the diode aspect. I know the diode is built into the FETs. So, if the FET simply shorts the phases, how can you eliminate the v drop of the diodes?

Diode conducts in one way only, if you close corresponding FET then you eliminate voltage drop associated with diode. ESC knows exact rotor position and then polarity of the BackEMF, this allows to use FET's instead of diodes to do the rectification.