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ToneWheel Hammonds use a synchronous motor to turn the ToneGenerator. A synchronous motor is a electric motor whose rotational SynchronousSpeed is locked to the AC line frequency. A motor consists of the armature built into the frame of the motor and the rotor which turns inside the armature.

The armature consists of copper windings that convert the incoming alternating current into a pulsating magnetic field. Organs used on 60Hz power systems use a six winding or "six-pole" armature. On a 50Hz power system, the armature has four-poles. A two-pole rotor turns inside the armature. The rotational speed of a synchronous motor is equal to (120 x Power Frequency) / No. of Poles in the Armature. So the rotor inside the six-pole armature turns at (120 x 60) / 6 = 1200 RPM. On a 50Hz organ, the rotor turns at (120 x 50) / 4 = 1500 RPM.

Before organs, Hammond made HammondClocks --- the first clocks to use the AC line frequency for a time reference.

Synchronous motors are not self starting: the HammondClocks have a knob in the back that one has to spin to start the clock. The Hammond organ patent application showed a hand crank on the side of the organ to start the motor! Wisely, Hammond added a separate inductive StartMotor which is used to get the ToneGenerator up to speed. See HowToStartAHammond.

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