- #36
Ratch
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toneboy1,
You still don't have it quite right. Yes, you can stall the motor and draw a fuse popping, wire burning, switch melting amount of current, but if the current is not in phase with the voltage across the motor, the power will not appear. I tried to explain that with my inductor example previously.
All motors will change the phase of their voltage/current if they have inductance.
The peaks are determined by the line frequency. That usually does not change.
The power will be greater because the voltage and current are in phase longer.
The "back EMF" is due to the collapsing magnetic field. Any motor type that uses inductance will have a back voltage. A motor will use more power if its voltage and current are in phase during more of the rotation cycle.
Are you sure about that?
You should start a new thread in the math section for that problem.
Ratch
So to summerise, the more resistance of a load on a motor, the more it increases the current, which makes it use more power.
You still don't have it quite right. Yes, you can stall the motor and draw a fuse popping, wire burning, switch melting amount of current, but if the current is not in phase with the voltage across the motor, the power will not appear. I tried to explain that with my inductor example previously.
So if it's an ac motor it will change the phase of the voltage or current,
All motors will change the phase of their voltage/current if they have inductance.
so the peaks will be closer
The peaks are determined by the line frequency. That usually does not change.
and I*V will be bigger,
The power will be greater because the voltage and current are in phase longer.
or if its DC then the back emf will decrease and it will use more power.
The "back EMF" is due to the collapsing magnetic field. Any motor type that uses inductance will have a back voltage. A motor will use more power if its voltage and current are in phase during more of the rotation cycle.
COOL. Exactly the sort of explanation I was looking for.
Are you sure about that?
If any of you (possibly clever engineers) could, I have an algebraic nightmare (a few of them) in this thread: https://www.physicsforums.com/showthr...=1#post4165324
I'd REALLY appreciate some help!
You should start a new thread in the math section for that problem.
Ratch
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