Dynators + dynamo charging rpm's

[jmp]

Started to put a few miles on the elan but if swmbo'd is going to use it regularly it will have to have an alternator. I'm tending towards a dynator but shying away with the expense. The cheapest I can find at present is still well into the ?300.00 plus range. Is there a recommended supplier at a good price that people are aware off.

What sort of tickover speed are owners with dynamo's running at?

I have a new dynamo on and at 1,000rpm it is still not charging on tickover.
Thanks,

John

[ardee_selby]

I have a new dynamo on and at 1,000rpm it is still not charging on tickover.
Thanks, John

Dynamo Data.jpg (31.96 KiB) Viewed 1193 times

This is the data from early Elan specs. (Guess it should be read in conjunction with regulator settings...but they are adjusted/set when running @ 3000rpm)

Maybe someone with more electrickery up their sleeves can help interpret further.

Richard

[billwill]

Elsewhere on the forum you will see mention that an alternator should have a smaller pulley on it so that it spins faster than a dynamo.

[Galwaylotus]

I have a new dynamo on and at 1,000rpm it is still not charging on tickover.
Thanks, John

Dynamo Data.jpg

This is the data from early Elan specs. (Guess it should be read in conjunction with regulator settings...but they are adjusted/set when running @ 3000rpm)

Maybe someone with more electrickery up their sleeves can help interpret further.

Richard

Just a note. The dynamo (or alternator) specs usually refer to the charger (dyna or alt) rpm rather than the engine rpm. The ratio of crankshaft pulley pitch diameter to alternator pulley pitch diameter needs to be applied to determine where the cut-in and maximum allowable engine speeds occur. Example: If the crank pulley diameter is 1.3 times the alternator pulley diameter, then at an engine speed of 1000 rpm, the alternator will be turning at 1300 rpm. It's also important to ensure that the charge warning lamp is still in the circuit as it needs that resistance to initiate the charging.

[jmp]

Thanks for the replys everyone. I'll carry out some research and seek further advice once I've done so.

John

[quaybook]

Hi John

I fitted one of Powerlite's Dynalite alternators last year. Expensive yes but an easy fit, no need to change fixing brackets or anything like that, and it leaves the under bonnet looking as it should. My car is positive earth as well and Powerlite are the only people I could find who do a positive earth alternator. Although the installation instructions said use the pulley off the existing dynamo I thought an alternator should be able to run at higher revs, so I checked with Powerlite and they agreed that it would be better to fit a smaller pulley. I therefore bought a standard alternator pulley from Matty and fitted that. Although expensive it is a great installation, all my charging worries are over (perhaps I'd better just cross a finger or two ), thoroughly recommended.

Vernon