- Joined
- May 10, 2014
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With all the reports around us of the V3's falling out of the sky or upgraded P2 with new ESC's and motors having the same problem.
I do not think its a "thin wire" issue, though this is a smaller problem.
Quite simply I think its a problem to with an incompatibility with the ESC and the new 2312 motors.
The motors are driven by the ESC's in a 3 phase way with activation of each coil inside the motor being energised in turn 120 degrees apart to give the direction and drive of the motor.
The control circuits need to know the position of the motor so it can correctly drive the next coil required to turn the motor.
To do this the position is determined by back EMF and sensed and reported to the CPU (Silicon General F330).
However with the higher power motor the detection of the position is getting misinturpreted so the mosfets are being energised incorrectly.
This has the effect of huge amounts of extra current being forced into the motor at the wrong time causing, either
A stutter of flight with minor loss of control for a couple of seconds.
A shut down of the motor and inadvertent reversal of motor or full stop, causing the propeller to unscrew and fly off.
A catastrophic failure of the mosfets due to excess currents.
The last 2 and possibly the first can cause the quad to destroy itself as we have seen.
The reason for the misinterpretation of motor positioning could be software or component tolerances of the ESC.
Either way DJI need to come up with a solution very quickly.
I do not think its a "thin wire" issue, though this is a smaller problem.
Quite simply I think its a problem to with an incompatibility with the ESC and the new 2312 motors.
The motors are driven by the ESC's in a 3 phase way with activation of each coil inside the motor being energised in turn 120 degrees apart to give the direction and drive of the motor.
The control circuits need to know the position of the motor so it can correctly drive the next coil required to turn the motor.
To do this the position is determined by back EMF and sensed and reported to the CPU (Silicon General F330).
However with the higher power motor the detection of the position is getting misinturpreted so the mosfets are being energised incorrectly.
This has the effect of huge amounts of extra current being forced into the motor at the wrong time causing, either
A stutter of flight with minor loss of control for a couple of seconds.
A shut down of the motor and inadvertent reversal of motor or full stop, causing the propeller to unscrew and fly off.
A catastrophic failure of the mosfets due to excess currents.
The last 2 and possibly the first can cause the quad to destroy itself as we have seen.
The reason for the misinterpretation of motor positioning could be software or component tolerances of the ESC.
Either way DJI need to come up with a solution very quickly.