Dynamo help

[Groily]

it didn't for some reason.Too long to cut and paste, will try to load some other way

[Groily]

The Dynamo System.pdf

should come up converted to pdf, no doubt with some small glitches!

[g5wqian]

Dynamo nudge circuit.jpg

Dynamo 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

[Groily]

That's neat, that is Ian! Like it - and not seen it before. Beats stray bits of wire any day!

[electrajohnt]

Ian and Groily, .
For the 10ohm 2 watt resistor what could I use.. I have access to 6v, 12v and 24v bulbs, or what do you suggest to create the required resistance.
JohnT

[Groily]

Subject to anything Ian might say to the contrary . . . I'd have thought a 6v speedo-type bulb should serve. Dunno what their resistance is, but not sure it matters all that much, it just makes the link from battery through the field winding non-brutal.
I'm going to try this on one of mine when I get a Round Tuit, because I also have one that can be slow to kick in after time off the road (sometimes takes a handful of rpm to fire up). 12v in my case - I'll try with an instrument bulb and holder for starters.

[Beefheart]

Super tip about linking battery to field with the engine running tried it yesterday on my very dead dynamo (53g3) bingo! we have life. Thank you Groily you have saved me a lot of money. I think it will be well worth while me adding the circuit shown by Ian. Also I have a much better understanding of dynamos after following this post. Thanks all.
Colin

[electrajohnt]

Gentlemen,
Would the attached do the nudging, I am assuming it would need to be permanently installed. I have chosen 12v because of the potential for uncontrolled 18v.
JohnT

06FDA777-0FF3-4FD5-B9F1-D4F17B6CC715.jpeg

[Mick D]

Hi

Wouldn't a straight push to make switch be a better choice than one that latches?

Regards Mick

[Groily]

You have a battery and a regulator, so there is no 'potential for an uncontrolled 18 Volts'. Any dynamo can produce far more volts than the system voltage it supports - wouldn't be much good if it couldn't.
The idea of the nudge is to get battery power momentarily to the field, gently, that's all - so there's not the same reason to use a higher voltage bulb as there is when testing a dynamo all on its own.

No idea what the resistance is of the LED in the gizmo - the idea here is simply to introduce a series resistance of adequate value between battery and field connection to dampen the hit to the dynamo when you shove the battery up it. A small filament bulb will do that; whether the LED would act as an equivalent brake, I just don't know.

Worth taking serious note too of Ian's point about battery drain through that regulator. This is a known common issue with some units, and does require the fitting of a battery isolator switch or disconnection of the battery when parked for long . It would be a boring double whammy to have a dynamo that wouldn't kick in and a battery so flat it couldn't nudge it!

And Yes to Mick's point, why latch it on? You don't need that.