It’s going to alternate directions, yes, but the power amplitude remains positive.
you’re saying the amount of power supplied is positive? what would negative power even imply in this context (trying to make the motor spin faster)
or maybe I’m misunderstanding, what is a “power amplitude”
yeah sure, but I’m saying each pole needs to be able to switch polarity as the corresponding rotor magnets pass them. as the magnets approach, the coils should be attracting it then as it passes the voltage on the coil reverses and so the coil pushes the magnet away, increasing torque delivery
He’s making up terms, or using entirely the wrong terms.
He means “zero volts” and “VCC” here, but is using watts.
I can mostly follow what he’s trying to get at from context, but holy fuck… Talk about speaking confidently from a place of authority after you obviously just jumped the silk rope.
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so then I’m wrong about the voltage being able to be negative then? am i also incorrect with this whole “push, pull” concept?
It depends on the reference frame, and the context.
The maximum instantaneous voltage across any two wires is going to be VCC-GND, yes.
But since there’s a three-phase full bridge (H-bridge), the controller can switch polarity so that any given magnet is either being driven “forward” or “backwards” by changing which phase wires see VCC and which see GND.
Basically, this whole discussion is a pedant’s pissing match trying to rationalize the naming convention of “brushless DC” motors by trying to call the not-sinusoidal-but-definitely-3-phase waveform “Not AC” and therefore DC.
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ah thats a good explanation, thanks
So we’re now back at the beginning where it’s an “AC”-Motor but its called DC because reasons lmao
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Probably the best description so far here
My cat’s breath smells like cat food
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Okay so I’ve never heard this, idk what it means, I gotta get it to the google-tron first thing in the morning.
But I get your jist, and I’m sorry I guess, for seeming to speak with authority. That was my mistake.
I guess I haven’t made it clear enough, and hindsight 20/20 I should have made a disclaimer before all this.
I don’t know much about motors, motor control, commutation or the function of an ESC
I’ve only recently been learning about it this year, through free resources.
I implore people to stop asking me questions. Go watch the playlist I linked. Join the VESC Development Discord server. Watch channels like GreatScott and Texas instruments on YT.
I’m some pleb that builds esk8s. Go learn from a professional.
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You could always just stop giving answers.
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Well, I’ve now tried pointing people to resources twice. It’s out there.
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Me building batteries with a pedant’s understanding of how electricity works…
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he explains the “AC vs DC” of it really well here
In my opinion, he doesn’t.
He speaks of the wave form as being “DC” when it’s trapezoidal and flat. but since the waveform on any particular phase does oscillate between negative and positive over time, it’s not DC. if you take what he’s insinuating there… every AC circuit is DC over short timescales, and sure, that’s kinda true.
but i don’t think you can conclude a DC motor is called DC because the current through the coils is DC, because the current int the coils is AC. (i’m re-convinced of that now. i faltered above. )
here’s where i’m at after watching the first several episodes of the playlist you shared earlier. (pretty good one)
i believe that @Linesflag has it right, with regard to the naming pedantry.
A brushed DC motor is powered by DC, and commutated by the brushes which pulsed the DC and formed an AC wave in the coils. so we call it a DC motor as the whole commutation and rotation was done in one thing, ie the brushes were part of the motor.
A brushless DC motor is powered by DC, commutated by the ESC which pulses the DC and forms an AC wave form same as brushed (or improved cause we can). but the ESC doing commutation is such a distinct part compared to the brushes in a “DC” motor, that it feels like it might be something different but for the pedantry of naming, I think we can consider them one thing.
And reminder, this i just my current understanding. i’m open to feedback.
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I have a question concerning different cell age in auxiliary battery. I have a 20S 8P with 25 cycles. I’d like to had another 20S 4P new. Soo it’s 25 cycle difference is it bad ?
In a perfect world, probably not. But we have no idea of the true condition of the cells in those packs so we can’t tell you it will be okay. It will have to be your decision based on zero data to go by.
Never joining the packs unless they are close in voltage and only using a good BMS for each can help though.
Nkon just got in stock, dont go with aliexpress its a gamble
Thanks, I will make sure to charge connect them with a delta of (0.015) volts maximum. Usually packs are never exactly the same. The cells am using are Samsung 21700 50E 5000Mah. They’re pretty good quality I don’t really worry too much about my existing pack health’s.
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