Author Topic: Stator wiring on a dragonfly  (Read 306 times)

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Offline andy1303

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Stator wiring on a dragonfly
« on: 30 Aug 2019 at 13:43 »
I have an odd issue with the stator on my dragonfly. A previous owner replaced the wiring to the stator in the wrong colours. So I've never been 100% sure everything outside of it was wired to it correctly. I decided to rectify this by rewiring it at the stator, but having removed the stator I have been met with an unexpected outcome. As noted on other threads, the correct wiring diagram shows 6 coils in the stator, all commoned on one side, but wired in a parallel group of four  and a parallel group of two. My stator is not wired like this. It is wired with with the group of four in two pairs of series-wired coils in parallel overall, and then the other pair also wired in series. The end result remains a group of two and a group of four with an overall common, but not wired as I would expect. Unfortunately my generator theory is non-existant, so I would value opinion on this. I have (hopefully) attached a sketch showing what I see, but note the colours don't match correct Douglas colours. It's worth noting that from the standard of the soldering (something I do know about) the configuration looks to have been original or done a long time before the rewire.
Thanks for any input

Andy

Offline Red

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Re: Stator wiring on a dragonfly
« Reply #1 on: 31 Aug 2019 at 10:11 »
Hi Andy

Have a look at the link below - Miller wiring diagram for the Dragonfly

https://www.douglasmotorcycles.net/index.php?topic=2868.msg10559#msg10559

Offline andy1303

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Re: Stator wiring on a dragonfly
« Reply #2 on: 31 Aug 2019 at 20:09 »
Thanks Red, but I have the diagram already. I'm hoping someone can tell me why my stator isn't wired in the same way as shown in the miller diagram and/or if it's a problem.

Andy

Offline eddie

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Re: Stator wiring on a dragonfly
« Reply #3 on: 31 Aug 2019 at 20:48 »
Andy,
          Are you sure you have a Miller stator? It could be either Lucas or Wipac. On the Miller stator, the coils are wired in parallel in banks of 2 and 4. On your stator, the coils are wired in series, effectively in 3 banks of 2. If the internal connections have been changed, you may have some coils giving a positive charge, while others are giving a negative charge, and cancelling out the positive ones!

  Regards,
                 Eddie.

  A problem I had was that the coils had become impregnated with finely ground bits of steel (from an engine blow up). Washing the stator and blowing it out with an airline cured the problem (until I started the engine, and the magnetic field generated lined up the particles, and hey prsto - we had a short to earth again). Eventually, I bought some 20 gauge copper wire and rewound the 6 coils. The generator is now wired for 12 volt and easily gives an 8 amp charge.
« Last Edit: 31 Aug 2019 at 20:56 by eddie »

Offline andy1303

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Re: Stator wiring on a dragonfly
« Reply #4 on: 01 Sep 2019 at 20:09 »
Thanks Eddie.
I wasn't sure what the results might be and the possible outcome you have mentioned makes sense. That said, it was running before, so I think getting it back together with the correct colours cables might at least enable me to work out if it's charging correctly.