Ahh doddy !
So simple and straight forward. How could I possibly get it wrong?

So our friends at Boxford chose a 10v output without any apparent resistor in series? or where did they hide it
And I guess I will have to use 12v so maybe will have to add a resistor, or maybe 5v but I will need to go back to my 1968 physics A level notes if I really want to understand your calc .

I can manage most mechanical stuff , and have a reasonable grasp of electrical machines , single and 3 phase, Even managed to get a handle on electronics in the days of thermionic valves , but I have to say that when the world turned upside down, when the time came when current stopped flowing from positive to negative and it was decided instead that current was a stream of negatively charged particles careering towards a positively charged source then that was the time at which my "electronic "head started to hurt .

What I am saying is you have to bear with me a bit while this stuff sinks in . When I get my new switches, I may need to come back with the spec, and ask you to turn forward voltage and forward current into a suitable source voltage / resistor combination.
Hope you haven't got too sick of me by that time