I showed the formula earlier. Any electrical engineer will verify this. If you reduce the field so much, the torque will eb so weka that the motor will not spin. It is possible to explode a motor. A series connected one is the classic on no-load or a differential compound one.
I showed the formula earlier. Any electrical engineer will verify this. If you reduce the field so much, the torque will be so weak that the motor will not spin. It is possible to explode a motor. A series connected one is the classic on no-load or a differential compound one.
messagenews: snipped-for-privacy@www.karpy.com...
of magnets; or modify the number of windings. Given
assuming torque is not even an issue ?
has to stay with a 12 vdc power source.
That will not change the flux. It will only reduce armature resistance and hence increase teh armature current. You will get more torque for sure but not more speed.
I don't think thats right. Changing armature current only effects torque. You would reduce armature resistance too and the back emf would go up and the speed woudl not change. You must change the armature voltage or the field -field is teh flux or magnetic strength.
messagenews: snipped-for-privacy@www.karpy.com...
of magnets; or modify the number of windings. Given
assuming torque is not even an issue ?
is has to stay with a 12 vdc power source.
Wrong!
The original question asked about increasing the speed "assuming torque is not an issue"
If torque is not an issue you are running the motor in a mode where its speed will be limited by BEMF, Reducing the number or armature turns means the motor will have to rotate faster to generate the ~12V of BEMF where motor current (and therefore torque) are in equlibrium with friction/windage etc.
Think of it as making your 12V motor into a 9V motor but still running it on 12V...
Peter Wallace
As I understand it, because you have reduced the number of windings, back EMF goes down. Back emf is not a function of resistance, it's only a function of the number of windings cutting the field as the motor rotates as I understand it.
The speed would increase because you have both increased torque, and reduced back EMF while keeping the field strength the same. The increased torque, acting against a reduced back emf, causes the motor to reach an equilibrium point at a higher RPM. At least that seems logical to me.
messagenews: snipped-for-privacy@www.karpy.com...
number of magnets; or modify the number of windings. Given
assuming torque is not even an issue ?
is has to stay with a 12 vdc power source.
Show me the equations first. This up a bit down a bit stuff is for amateurs. Motor current and torque are in equilibrium? Torque is proportional to armature current. Please show your equations to back up the claims. A steady-state model will do.
hardy
messagenews: snipped-for-privacy@www.karpy.com...
number of magnets; or modify the number of windings. Given
assuming torque is not even an issue ?
that is has to stay with a 12 vdc power source.
Please read what I wrote a little more carefully Maybe then you will understand what I said but then again, maybe not...
Peter Wallace
messagenews: snipped-for-privacy@www.karpy.com...
number of magnets; or modify the number of windings. Given
assuming torque is not even an issue ?
that is has to stay with a 12 vdc power source.
Means you have no idea!! The design of electrical machines has been well defined by simple equations for at least a century or more and yo ucannot state your point. I take it you are not an electrical engineer.
Hardy
I take it you are unable to read
Please read what I wrote again (slowly)
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