"A E" wrote in message
...

dave's theory was that a diode was more 'efficient'
than a resistor, which doesn't compute.

OK, cheerfully withdrawn! Maybe it was a bad choice of words. Let's just say
IMO a diode is a cleaner way of dropping voltage because a 0.6V drop
(approx) can be predicted, and all available current is still available,
unlike a resistor. I'm well aware of the maths regarding dissipation, on
reflection I didn't really say what I meant.

Dave