Thanks for the feedback. I agree that it would be wisest to keep to the 22 amp
limit despite the possibility of wringing a couple more amps.
Of course I am making the current draw judgements based on my car's ammeter
whose reading is approximate at best. Still, I think that full scale charging
PLUS lights is over 22 amps no matter what!
I am going to get that semiconductor-based regulator and test it out. Since it
is completely contained within the original control box and uses the same
terminals, it will be totall invisible.
I wonder how/why my regulator comes to so significantly exceed the current
specifications. I suppose the same number of turns of the wire using a
slightly larger diameter will allow more current for the same magnetic field.
Or, maybe I simply have the wrong regulator and it is designed for more
current....
The other issue is that unless I had a depleted battery, and was away from an
AC charger, it would not matter what the regulator woud do because I would
never draw more than 22 amps anyway.
Well, I will get something that is tested to give the correct voltage AND
current limits!
-Tony
-------------- Original message --------------
> > So, What is really the maximum continuous current rating for our
> > generators? I would assume that 22 amps is the limit based on what I saw
> > in the specifications page of the Haynes manual. But my present regulator
> > is allowing more than that! I am going to order one of these electronic
> > regulators and I want to specify the highest safe current limit. So, what
> > should I tell him?
>
> I honestly don't know the answer to that, Tony. Personally, I'd be leery of
> exceeding the 22 amp (19 for earlier units on TR2/3) rating for very long;
>since
> I know from personal experience that it's not hard to burn up a TR generator
>in
> 30 or 40 minutes of continued high-speed overcurrent operation.
>
> I believe the original circuit worked as well as it did because the old
> batteries' charge voltage would rise fairly quickly to at least 13v or so, in
> less time than it took for the generator to overheat and start throwing
>solder.
> And sometimes, of course, it simply let the generator burn up. I've never
> understood the decision to use the 2-coil regulator on the TRs, especially
>since
> a 3-coil unit was used on Spitfire (and Vitesse).
>
> Unless you're willing to test several units to destruction, my suggestion
>would
> be to give him the factory rating and consider yourself lucky that your 'hot'
> regulator didn't burn up the generator. I suppose the ultimate setup would be
> to measure the internal temperature of the generator (and limit it), perhaps
>by
> measuring the field coil resistance ... but it hardly seems worth the effort
>to
> me...
>
> Randall
|