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Interesting, thank you Tcmtech
but how can i be sure ?
That would be the sine-wave frequency for a single-phase generator.Crutshow:
frequency (Hz) = cp * RPM/60
cp=couples of poles
it is correct ?
Yes, I would like to resolve this too.Thank you all,
the frequency shown by Crutshow seems (to me) the right one for full wave rectifier (6 diodes) as usually found in the car's alternator.
The frequency shown by Spec seems (to me) the right one for half wave rectifier (3 diodes): there are some alternator, in automotive area, with this ? I don't know.
Any feedback is welcome.
The winding direction is such as to make one side of the rotor (one claw) one magnetic pole and the opposite side the opposite pole.Do you know, I have never bothered to figure out how you get N poles from a single winding on an automobile alternator rotor. Also, the winding direction seemed to be wrong. Your picture makes the technique crystal clear.
There is the factor "cp" (pole pairs) in my formula.Crutchow's formula, in post #11, does not include the contribution to the ripple by the number of poles, just the contribution of the three phase (x3) and the full wave rectification factor (x2).
There is the factor "cp" (pole pairs) in my formula.
I didn't mean that the single rotor winding was backwards. The rotor winding is in the wrong direction (orientation) and, without the magnet ears, the rotor coil magnetic field would not cut the stator coils at 90 Deg. If I haven't explained that correctly, I hope I have conveyed the principle.The winding direction is such as to make one side of the rotor (one claw) one magnetic pole and the opposite side the opposite pole.
How is that backwards?
I believe you misunderstand how the rotor works.I didn't mean that the single rotor winding was backwards. The rotor winding is in the wrong direction (orientation) and, without the magnet ears, the rotor coil magnetic field would not cut the stator coils at 90 Deg. If I haven't explained that correctly, I hope I have conveyed the principle.
I did get that Cruts. But thanks anyway.I believe you misunderstand how the rotor works.
The magnetic ears are indeed integral to its operation.
One claw is magnetized with one magnetic polarity and the other claw with the opposite polarity by the coil between them.
It is the magnetic ears of the two claws that generate the field between the claws that cut the stator coils.
(The field direction is not exactly 90 degrees to the stator but I don't think that has a significant effect on the operation).