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Excerpted from the OriginalHammondLeslieFaq

The tone generator assembly consists of an AC SynchronousMotor connected to a drive shaft which turns a series of DrivingGears. Meshed to the driving gears are DrivenGears which turn a series of tonewheels. Each ToneWheel rotates adjacent to a MagnetAndCoil assembly (similar to an electric guitar pickup). The number of bumps on each ToneWheel times the GearRatio times the rotational speed of the motor determines the pitch produced by a particular tone wheel assembly. The pitches approximate even-tempered tuning, (it's done with integer math after all).

Each ToneWheel Hammond Organ has a main ToneGenerator within it, and in some cases, depending on the model, a ChorusGenerator. Depending on the model and the year it was built, Hammond tonewheel organs had different TypesOfToneGenerators.

The AC synchronous motor is connected via a resilient CoilSpring coupling to a drive shaft extending the entire length of the generator.

Twenty four brass driving gears (2 each of 12 sizes) are mounted on this shaft with resilient coil spring couplings. Each driving gear turns two bakelite driven gears which each turn two tonewheels.

Of the 96 tonewheels in the most popular Hammond models (B-3, C-3, A-100 etc.), 91 are 'true' tonewheels -being used for sound generation, with the other 5 being balance wheels. A few Hammond models (Grand 100, E-100, H-100, etc.) used all 96 tonewheels for sound generation. One Hammond model, the X-66, used a tone generator with only 12 tonewheels.

Each driving gear, its two driven gears and four tonewheels run in a compartment magnetically shielded from the others, by steel plates which divide the generator into a series of bins. All tonewheels in a compartment turn at the same speed but have different numbers of bumps so the tonewheels in a compartment are therefore harmonically related.

AC SynchronousMotors are not self starting. In Hammond clocks, the synchronous motors were started by manually spinning a small knob in the back of the clock. In the original patent drawings, the organ is shown with a hand crank in the side of the organ to start the motor! Fortunately, all production models have included an AC induction StartMotor to start the organ. The StartMotor is mounted near one end of the drive shaft, the SynchronousMotor being at the other end. (Or, on some later models, a self start "Blue" motor is the only motor.) The drive shaft on the StartMotor side of the shaft also turns the scanner Vibrato.

Each ToneWheel rotates adjacent to a MagnetAndCoil assembly.

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