Author Topic: test dynamo  (Read 2362 times)

Offline Tumbleweed

  • A's Good Friend
  • ***
  • Join Date: Feb 2012
  • Posts: 226
  • Karma: 0
test dynamo
« on: 30.08. 2018 14:48 »
hi everybody  .  I am trying to make a good dynamo out of two old ones .  when I spin it with a drill A/Clockwise I only get2-3 volts set on  20 position on my  meter joining F and D together  to  neg   and pos  to + it wont light a bulb just a faint glimmer, but it motors quite fast.        any ideas TW  how fast does it have to turn befor it works with the dynamo off the bike
Semper in excretia sumus solum profundum veriat.

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5720
  • Karma: 66
Re: test dynamo
« Reply #1 on: 30.08. 2018 15:39 »
Quote
oining F and D together  to  neg 


Dynamo body would be neg or pos depending on polarity usually positive earth on these bikes
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Tumbleweed

  • A's Good Friend
  • ***
  • Join Date: Feb 2012
  • Posts: 226
  • Karma: 0
Re: test dynamo
« Reply #2 on: 30.08. 2018 15:53 »
 yes Bill its off my a10 and its +earth  , 
Semper in excretia sumus solum profundum veriat.

Online JulianS

  • 1962 A10
  • Wise & Enlightened
  • *
  • Join Date: Mar 2017
  • Posts: 1382
  • Karma: 29
Re: test dynamo
« Reply #3 on: 30.08. 2018 18:14 »
Lots of interesting stuff on electrics on Matchless Clueless site;

https://matchlessclueless.com/

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5720
  • Karma: 66
Re: test dynamo
« Reply #4 on: 30.08. 2018 18:14 »
a week or so ago I got similar results before changing polarity back to positive earth (long story)  , turned out I had painted the dynamo not thinking about it's need to earth, had to rub of the paint (under the strap) and put a piece of copper between the strap and the dynamo, magic upto 20 volts at times
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online trevinoz

  • Newcastle, N.S.W. Australia.
  • Wise & Enlightened
  • *
  • Join Date: Jul 2006
  • Posts: 3183
  • Karma: 71
Re: test dynamo
« Reply #5 on: 30.08. 2018 22:33 »
That is usually indicative of an armature with open circuits.

Offline Tumbleweed

  • A's Good Friend
  • ***
  • Join Date: Feb 2012
  • Posts: 226
  • Karma: 0
Re: test dynamo
« Reply #6 on: 31.08. 2018 09:45 »
thanks for your help chaps ,  the matchless site was useful as well     TW
Semper in excretia sumus solum profundum veriat.

Offline Tumbleweed

  • A's Good Friend
  • ***
  • Join Date: Feb 2012
  • Posts: 226
  • Karma: 0
Re: test dynamo
« Reply #7 on: 03.09. 2018 13:38 »
hi, everybody ,  I have just run a test with a electric drill and at 2000 rpm    I get  14 v charge from it I am hoping this will do for my a10 ?    TW
Semper in excretia sumus solum profundum veriat.

Offline Rex

  • Wise & Enlightened
  • *
  • Join Date: Apr 2017
  • Posts: 1534
  • Karma: 7
Re: test dynamo
« Reply #8 on: 03.09. 2018 18:54 »
a week or so ago I got similar results before changing polarity back to positive earth (long story)  , turned out I had painted the dynamo not thinking about it's need to earth, had to rub of the paint (under the strap) and put a piece of copper between the strap and the dynamo, magic upto 20 volts at times


It should earth just fine through the ally end plate to the engine.

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5720
  • Karma: 66
Re: test dynamo
« Reply #9 on: 03.09. 2018 19:02 »
Quote
It should earth just fine through the ally end plate to the engine.


Really , I find on mine the cork gasket makes a good insulator  ;)
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Rex

  • Wise & Enlightened
  • *
  • Join Date: Apr 2017
  • Posts: 1534
  • Karma: 7
Re: test dynamo
« Reply #10 on: 03.09. 2018 21:16 »
Mine must be a different design then, as the cork gasket only touches in the middle section and the outer portion is well and truly butted up to the crankcase.

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5720
  • Karma: 66
Re: test dynamo
« Reply #11 on: 03.09. 2018 21:20 »
possible the cork has compressed, if the alloy touches first then the cork is doing nothing.
The reason mine did not earth was I had stupidly painted the body ( a bit too well)
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online trevinoz

  • Newcastle, N.S.W. Australia.
  • Wise & Enlightened
  • *
  • Join Date: Jul 2006
  • Posts: 3183
  • Karma: 71
Re: test dynamo
« Reply #12 on: 03.09. 2018 22:42 »
TW, if you are getting 14V the generator is fine.

Offline coater87

  • Wise & Enlightened
  • *
  • Join Date: Jul 2008
  • Posts: 1204
  • Karma: 6
Re: test dynamo
« Reply #13 on: 04.09. 2018 15:29 »
 After some of the hassle I had with mine after rebuild, I would power up a bulb with it before I buckled it up. 14V is nice, but I would make sure it will run a load first.

 Lee
Central Wisconsin in the U.S.

Offline Tumbleweed

  • A's Good Friend
  • ***
  • Join Date: Feb 2012
  • Posts: 226
  • Karma: 0
Re: test dynamo
« Reply #14 on: 11.09. 2018 12:16 »
hi folks ,   well I fitted  it to the bike and I don't even get 1 volt direct from dynamo    *sad2*  also I  flashed the F terminal for polarity ,  the D terminal flashes as well  is this normal ?   TW
Semper in excretia sumus solum profundum veriat.