I don't understand why single phase ac motors need start windings? I know they do, but there is something I'm not getting.
It seems to me the stator poles produce a constantly changing magnetic field which induce a VOLTAGE across the windings, or squirl cage of the rotor. Since the impedance of the rotor is almost purely inductive, the current, and therefore the resulting magnetic field of the rotor should lag that voltage by ~ 90 degrees. Therefore the two magnetic fields of the stator, and rotor should be displaced by ~ 90 degrees, and therefore no need for start windings.
I know I have something wrong, but I don't know what it is. Can someone please straighten this out for me?
It seems to me the stator poles produce a constantly changing magnetic field which induce a VOLTAGE across the windings, or squirl cage of the rotor. Since the impedance of the rotor is almost purely inductive, the current, and therefore the resulting magnetic field of the rotor should lag that voltage by ~ 90 degrees. Therefore the two magnetic fields of the stator, and rotor should be displaced by ~ 90 degrees, and therefore no need for start windings.
I know I have something wrong, but I don't know what it is. Can someone please straighten this out for me?