McFadyean wrote:
>
> For the Rotax alternator with permanent magnet field, none of this is
> needed. So a LED will do without any paralleling resistor. Series resistor
> may be needed however, typically 600 ohms or thereabouts depending on
> voltage.
Inoperative, there's infinite resistance to ground; operative it has
to go high to bus voltage so the lamp won't light. But it does
measure one semiconductor junction's worth to ground on a diode check,
so I think I know what's in there. A dummy resistor load will surely
work, but wastes current. I think just an LED to the "L" terminal
will work, but having not gambled in many years, I've lost the ability
to spot a good 1 to 5 shot.
Another thought is that they call these idiot lights on cars. Best I
think is volt and amp meters, as the alt lamp may not identify all
faults. Circuitry to add aural/visual alerts on overs and unders
isn't too complicated, even w/o meters, if so capable or desirous to
learn another hobby.
Best,
Fred F.
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