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dynamo

Posted: Mon Mar 21, 2011 8:22 pm
by win
I am unable to get my spare dynamo to charge, I am checking it off the car.
Am I doing any of the following wrong?

I try the dynamo by connecting F and D together, and then a 12v bulb from them to earth, spin the dynamo at 700 to 1000 RPM. the bulb does not light, checked with meter, no voltage.

The field coils read 6 ohms to earth.
The brushes are in good condition, and free in the holders.
There is a circuit from D to earth, which goes open when the earth brush is lifted off the com.
When the com is removed, it looks in good condition, clean and bright, no burning marks, or visible damage, and the segments are not down to earth.

I have "FLASHED" the field coils, by earthing the body, and stroking the + lead across the F connector.

Not sure how to check any more, any help appreciated.
Regards Win.

Re: dynamo

Posted: Mon Mar 21, 2011 9:45 pm
by bmcecosse
Join the D and F - then connect them to the battery +ve with a jump lead -and another from the -ve earth to the casing. If it 'motors' - it's working!

Re: dynamo

Posted: Tue Mar 22, 2011 4:24 pm
by win
Hi
Joined the D and F then connected them to the battery +ve with a lead and another from the -ve earth to the casing.
It ran just like a motor, fitted to car, it charges just fine. GREAT.

I still cannot understand why no measurable output on the bench, but I will add it to the long list of other things, I dont understand.

Thanks once again.
Regards Win

Re: dynamo

Posted: Tue Mar 22, 2011 4:46 pm
by bmcecosse
I guess it needs an initial voltage to get the 'field' going - and then once started it would be self sustaining.

Re: dynamo

Posted: Tue Mar 22, 2011 5:15 pm
by Alec
Hello Win,

"I guess it needs an initial voltage to get the 'field' going - and then once started it would be self sustaining."

Particularly if it's not been working for a while.

Alec

Re: dynamo

Posted: Tue Mar 22, 2011 5:52 pm
by win
Hi
That makes a lot of sense.
off to the pub to celebrate.

Regards Win

Re: dynamo

Posted: Tue Mar 22, 2011 7:34 pm
by bmcecosse
Win did say he had flashed the field coils-------but maybe not for long enough to cause sufficient latent magnetism to start the current flowing.

Re: dynamo

Posted: Tue Apr 26, 2011 8:53 am
by Jim Collins
Hi Guys. I am trying to sort a friends 1932 morris minor out. It appears that the dynamo is working but the cut out/regulator is not pulling in. Does anyone out there have a spare 6V cut out? It has 5 screw in terminals. The owner is not fussed about it being original, just reliable. So if there is a modern alternative, I'd be happy to know what it is and where I could get one from. He lives in the midlands. Thanks for your help.
Jim

Re: dynamo

Posted: Tue Apr 26, 2011 4:28 pm
by PSL184
Hi Jim
Mainly Austins but may be the same on the Morris....
Try Bob at :
AVAILABLE AUSTINS (Bob Glenister)
Address: Station Road, Old Arley, Near Coventry, CV7 8FG
Phone: 01676 541276
Fax: 01676 542066

Re: dynamo

Posted: Tue Apr 26, 2011 5:33 pm
by Jim Collins
Cheers mate. I will try Bob in the morning.
Regards,
Jim