Homopolar generator with co-rotating magnet

[Cadman]

Each magnet's field would be concentrated in the gap between that magnet's N & S pole. Since those gaps orbit with each magnet, so would the field.

[LeoFreeman]

Ideally, the poles of the magnets should form a continuous ring. The Faraday wheel works even if the magnet co-rotates with the disk,
so that part should be the same.

The main big difference in this device, however, is in the way the magnetic field is confined to the horseshoe magnets,
as compared to Faraday wheels that simply use open-ended magnets, where the stray field can cause back-emf in the current conductors if they move through it

The big question is: Can an electric current in a wire pass unaffected through a region of magnetic field, 
IF the field is confined to a high-permeability material,
AND the wire passes through a gap in the material, so that the flux lines are ducted around the wire?      .

[LeoFreeman]

Here is another version that may achieve a higher output voltage, by having many loops
of wire in a sinusoidal pattern. (only one full loop is shown here, but the sinusoidal pattern
would be repeated many times around the disk.
The applied magnetic field changes direction on each Inward and Outward going section of the wire,
so the electrons are pushed in the same direction, until the wire exits towards the light-bulb at
the centre.