Misc: Charging Systems Miller Dynamo Field Coil

LoneStar

LoneStar

Well Known and Active Forum User
VOC Member
Hello all,

I long ago acquired a partly-disassembled Miller D6 dynamo, and now I'm trying to make a working unit out of it. I plan to use an electronic regulator, so the internal wiring will be the simpler Lucas-style arrangement without the Miller cutout unit.

My problem is identifying the wires from the field coil. The Miller design apparently includes an extra resistor of some sort within the coil, and so there are 4 wires coming out of the unit rather than the 2 you might expect.

D6_shell.jpg

Looking at the photo, there are two pair of leads that have low resistance between them: yellow -black (3.7 ohms) and green - blue (3.4 ohms). No wires connect to the shell, and resistance between all other combinations of wires is infinite.

Does anyone know which wires connect directly to the field coil?

Thanks!
 
greg brillus

greg brillus

Well Known and Active Forum User
VOC Member
No the second winding is normal for the original field coils........The main winding should show around 4.7 to 5 ohms resistance.........The second winding is only a handfull of turns around the main winding........We use to strip off the cloth insulation and remove the winding all together, then renew the cloth insulation.......Not too hard once you manage to undo the pole screws, but these are usually very tight. The connection of the 2 field wires dictates the direction of armature rotation, so simple to swap around if the genny does not spin the correct way when you test it by "Motoring it on the bench" before re installing it on the bike.
 
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