Maybe its called that because the source of energy is usually a DC source? Because you defo can’t drive a EC-motor with DC.
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yeah i think so
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havent heard this term before, do you mean this: ?What is an Electronically Commutated EC Motor? - Continental Fan
That implies a direct supply though, which is misleading I think.
Yes, this is the most correct term I think.
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ehh yeah maybe. i think its semantics tho
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Yeah, all of this is sematics. 
Important ones too, I believe.
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seems like these guys say that an “EC motor” is a type of AC motor because you can plug it into an AC source like what you get from a wall socket. They imply their “EC” motors are BLDC motors with some electronics attached to the housing. They say the electronics include a rectifier, which to me implies that it is natural to say BLDC motors do not naturally use AC as source. (since they first have the need of converting it to DC before use by the motor “inverter”.
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I guess it really just comes down to what you consider to be the “Supply”. is the supply the power source (like a power supply) or is the supply the ESC since that is what is closest to the motor’s coils electrically speaking.
Which is a device that converts DC to AC. I guess your source is a bit ambiguous about the definition, wikipedia says that a BLDC motor is an EC motor.
I guess switched DC does not officially count as AC then? I feel like I’m falling into a deep rabbit hole here…
I think because BLDC motors derived from brushed DC motors they are still counted as such, because the brush operation is done electronically instead of mechanically.
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i’m riding along. i felt very muddled in a previous attempt down this path.
does this suggests the the motor + the ESC to do this switching make up it being a BLDC motor?
i like this take.
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Because the controller implements the traditional brushes’ functionality
Just found this part in the article. I think I can accept this as a conclusion.
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Because the 3 sine waves of power sent over the phase wires are all in the positive half of the amplitude graph.
With AC the amplitude alternates between positive and negative amplitudes. For the purposes of commutation, our motors are “DC”
Many companies refer to brushless AC motors as PMSM (Permanent magnet synchronous motors)
Effectively, both are constructed similarly and you can run either one with AC or DC commutation, with varying degrees of efficacy.
Really the main difference is trapezoidal vs. sinusoidal BEMF
I’m shit at explaining this stuff, I highly recommend watching this playlist if interested:
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This makes an even better rational for calling them DC motors.
but for some reason I thought this wasn’t true. i thought there some coils had to have their magnetic fields flipped so there was a bit of push and pull going on magnetically.
so i guess this is wrong.
No. The phases are only capable of a differential between 0W (ground) and the SOC (Watts) of your battery. No more and no less.
It’s wrong if you’re using DC commutation but not if using AC commutation. AFAIK the “AC or DC” of motors has more to do with how power is being sent to them.
Motors can have concentrated windings or distributed windings, which causes BEMF to be more trapezoidal or sinusoidal. Typically trapezoidal BEMF motors are referred to as “BLDC” and sinusoidal BEMF motors are referred to as PMSM or “AC motors”
There are also various core designs and things like helical magnets that also affect the BEMF.
Thing is, BLDC “trapezoidal BEMF” motors have become so good the BEMF is almost sinusoidal anyway and these motors are like hybrids with all the advantages.
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it though that it was the case that with field oriented control all 3 of the phases are all energized pretty much all the time, but to different extents and polarities. This allows for both “push” and “pull” field interactions which results in higher torque output
yes, with FOC all 3 phases are powered above 0W to take advantage of optimal torque vectors. this doesn’t preclude the fact that all 3 phases are still of positive amplitude in our case.
ah, and i’m seeing now because of the way the coils are wired, with an all positive amplitude wave form, we can still get one coil with one polarity and the other with the opposite.
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however, if we send a signal from B-A, then A-C, isn’t the DC current going alternate directions in coil A ( in the first diagram ) and this is the AC signal on the phase wire people are talking about?
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