It's rare, but it is done in very small sizes.
Motor is built with two identical windings but displaced by 90 degrees or
so. The two windings have a common end connected giving three terminals, one
to each winding and one to the junction of the two.
Because the windings are identical, you energize one from the line and one
through a cap and the motor turns in one direction. Reversing the direct
and capacitor connections reverses the motor. This can be accomplished by
wiring the cap across the two winding leaads, and moving the hot supply leg
from one to the other. Neutral supply leg goes to the junction of the two
This is typically used in small synchronous gearmotors, typically less than
1/10 hp or so. Starting torque is not great, due to the need to make the
windings identical. Bodine used to make lots of motors like this.
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