Is that 40 m of lights, or 40 m to the first light please?

There are 9 different lights attached, all at around 5-10 watts each, all branching off along the route, the total length is 40 metres. Even with the first few being compliant, I don't think it will any good for the last few, as the voltage will be down to 6V or less.

There are 9 different lights attached, all at around 5-10 watts each, all branching off along the route, the total length is 40 metres. Even with the first few being compliant, I don't think it will any good for the last few, as the voltage will be down to 6V or less.

I have had a bit of a think about this one and I think that the answer is not easy. As you go along the cable, the load decreases, so the VD is not uniform. Moreover, what assumptions can be made about each lamp? If the voltage drops, do they draw less current (rather like a filament lamp) or does the circuitry try to keep the power constant?

Then if you think about an LED headlamp or torch, they do seem to work with a significantly reduced voltage, albeit dimly.

I suspect that Alan's original conclusion is correct: mains voltage cable and local transformers, which is rather like the way that DNOs distribute their power.