Author Topic: Dynamo checking  (Read 570 times)

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Offline C11Andy

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Re: Dynamo checking
« Reply #15 on: December 27, 2018, 11:15:14 am »
Ron, I had charging problems on my C11, even with a new regulator (dvr2) and a professionally reconditioned Dynamo. Sometimes it would charge, sometimes it wouldn’t. Eventually I did something that Richie recommended and connected up a 2W speedo bulb as a charging light (just bundled it up and hid it under the seat). I can’t remember the exact connections as I have since sold my C and all these details went with it, but if you look on many of the C wiring diagrams of the 50s you will see a charge light shown. Once I did this it worked perfectly every time.
Basically the dynamo relies on at least a small residual magnetism to kick start it into life and over the years this residual magnetism is no longer retained. By putting the bulb in place it drew just enough current to create a small electric field and hence provide enough magnetic field to kickstart (bootstrap) the Dynamo.
Might be worth trying just as an experiment, ultimately if it works you can hide the bulb somewhere, even inside the headlight, so it doesn’t spoil the external authenticity of your bike. As soon as the dynamo starts charging the bulb goes out anyway.

1953 C11
1958 Ariel NH
1959 T100A

Offline timsdad

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Re: Dynamo checking
« Reply #16 on: December 27, 2018, 01:02:32 pm »
I bought two AO regulators, for B31 and Real C12, because I thought they'd do the job, I believed the blurb on his web site and he only lives twenty miles from me.

The B31 reg. was replaced twice with a new one, although he insisted my bike was at fault. When he got fed up with checking them out on his bench he finally admitted that they could be temperamental if the voltage dropped below the low sixes and, if it did, the regulator would not kick in until the battery was charged right up again. Before this showdown, I rode the B31 round for several weeks with a multi-meter duct taped to the tank so I could monitor the voltage and get an actual indication when it stopped charging independent of the ammeter. No more problems after I fitted a Boyer regulator.

I persevered for some time with the AO-kitted C12, spare battery in my pocket and no lights used, but it ran out of volts between Norwich and Cromer one fine day. The spare battery got me back as far as Wymondham (pronounced Wind-um for you Southerners) until she came to a halt. Got another mile after a rest but then a pal had to come out and pick me up. All Alan Osborn's fault so it got a DVR2 the next week. I would never trust another.

The obvious answer is to try another known, good regulator and try your suspicious ones on another bike. You've got a shed full of spares!


Just a motorcyclist.

Offline Tman

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Re: Dynamo checking
« Reply #17 on: December 27, 2018, 04:16:53 pm »
We've been down this route before, and I too wouldn't ever consider buying another AO thing.
I never quite understand how "the well-respected bike electrical guru" Paul Goff can sell and endorse the crappy things.
{Maybe it's because both Goff and Osbourne have no customer skills, to put it politely ;)  }
In my personal experience, they're just as useless as the Indian-made electro-mechanical regulators, so it's either a known good old reg or a DVR2 unit for me.

Offline MilitaryRon

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Re: Dynamo checking
« Reply #18 on: December 27, 2018, 04:53:00 pm »
I totally agree and will never buy another AO regulator, but as I'd bought this one before we knew the faults, I thought I might as well give it a go. Also I've had one on his on my M20 for probably 10 years without a hitch.

Anyway getting back to my charging issue. I exited the field coils as suggested by John and I'm even more excited that it started charging. I'm getting 6.9V on my cheapo multimeter ( I must buy a new one with the continuity facility). The headlamp goes bright when I rev up. It's good enough for my needs!

I'm now going to re-visit the clutch which still slips when kicking through compression.  >:(

Thanks all. Ron