Dynamo help

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electrajohnt
Posts: 136
Joined: Wed May 08, 2019 7:41 pm
Location: UK

Re: Dynamo help

Post by electrajohnt »

g5wqian wrote: Thu Jun 17, 2021 7:57 am Dynamo nudge circuit.jpgDynamo nudge circuit.jpg

this is taken from the ariel owners page .

dynamo nudge circuit .

might be on interest if you are wanting to kickstart the dynamo circuit using it .

i have a wassell voltage reg on my ariel single and a dvr2 on my ajs twin , the wassell regulator does draw about 50-60ma of current when not charging , so it will drain the battery within about 3 days .
i disconnect my battery when not using bike , then it stays charged , but if you want to better regulator that doesnt draw any current as such then get a dvr2 or a vreg from AO services .

i have both a dvr2 and vreg2 which i am going to swap to though .

even on 6 volt i find you need revs up to get it charging at a decent rate , i think typically 3000rpm for 2 amps on the meter .

i use LEDs front and rear , they draw less than 1 amp combined .

regards ian
I have installed in accordance with this, not had the engine running yet, another problem, but with battery connected and all seems ok when I press the nudge button ( lovely term that) the light does not shine. Is this ok taking into account no engine (dynamo) turning?
JohnT
JohnT
Groily
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Location: NORMANDIE FRANCE

Re: Dynamo help

Post by Groily »

Hmm. It should light regardless. The bulb is in circuit with the field coil when you press the nifty nudger, so current should flow from the battery through it and thence to earth via the coil.

If you directly earth the wire that's meant to go to F and then press, does it light?
If it doesn't, there's no power supply, a duff bulb, a wiring thing in the button or bulb holder, or a poor connection in the dynamo.

If it does light when earthed directly, then check the connection to the F wire or terminal.

If it still doesn't, check the field coil earth at the dynamo - one wire off it is attached to the dynamo by a small screw, along with the tail of the earthed brush. (The other, of course, going to the back of the F terminal.)
electrajohnt
Posts: 136
Joined: Wed May 08, 2019 7:41 pm
Location: UK

Re: Dynamo help

Post by electrajohnt »

Nudge, nudge, wink, wink.
The nifty nudger works. It was a bad connection in the bulb holder, it was ok when I first tried it on a battery (Chinese, cheap but you pays the price?!). Pressed the nudge button with a few revs on and alive it came. 4amps initially and subsides to 2amps. when stopped with very low tick over I had to re-nudge once I got going again. Not a big output but better than before.
Thanks again to Groily, Ian and all others who took an interest in my problem.
Still learning, so can’t be bad eh?
JohnT.
JohnT
Groily
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Re: Dynamo help

Post by Groily »

:D :beer:
electrajohnt
Posts: 136
Joined: Wed May 08, 2019 7:41 pm
Location: UK

Re: Dynamo help

Post by electrajohnt »

Can I resurrect this topic please.
Using the nudge button at every start up the system will just about hold its own with a few revs when pilot light and tail light are on. When the headlight is on it goes substantially into the minus side of the amp meter. Oddly, when I press the rear brake to activate the brake light the amp meter goes positive with the pilot light on and less negative( but still negative) when the headlight is on.
Why would it do that. Is it a bad earth somewhere, although things seem to work ok normally when engine not running.
JohnT
JohnT
Groily
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Re: Dynamo help

Post by Groily »

If I remember this right John, this is a 45 W dynamo on a Velo that would have had a 60 W Miller on it?
Nothing wrong in that, on the face of it, but what is the wattage of your headlamp? If you add that up with the other lights, how close are you to max output? Even a modest 36W bulb + tail & speedo etc is getting close to the rated output . . . anything more than that is going to be hard to support I would think.
Does it ever get the ammeter to 0, even at 'open road' revs I wonder? If it doesn't, then there might be some wiring issue or a performance problem, yes (can't say from far away obviously) but as I think I also wondered earlier on - what is the gearing of the dynamo? Typically, they go round at about 1.25 times engine speed. Any less and it might be a problem? Is the pulley the original size?
That said, if the total wattage being demanded is within limits, and the thing never balances with the headlamp on, and if there isn't a short anywhere, then it does seem as if the dynamo may have seen better days. Does it still light up your bulbs on test OK, or does it struggle now?

On the ammeter movement - If the brake light is wired directly from the battery, then when you apply the brake the ammeter will register a positive movement because it senses there is a battery drain (and although it's not shown on the ammeter because the brake light isn't wired through it, the regulator senses it and compensates for it). It's one way of knowing the dynamo is charging in fact, as you ride along - and 'they all do that sir'.
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