thank you thats excellent. I take it the Magic thing is the light sabre hilt?

Correct. You are welcome!

Would one of these be a good fit for this application? I'm thinking maybe I could run all 3 light savers of one supply? amazon.co.uk/Guitar-Pedal-Power-Supply-Overcurrent/dp/…

Most likley yes. The 9 V relay will be the hard part to find. 5 V is common as well as 12 V. 9 V isn’t. If you only plan on handcrafting one single contraption like this, I would suggest trying various 12 V relays until you find one which is happy at 9 V.

amazon.co.uk/ProTechTrader-9vdc-volt-Relay-Non-Polarized/dp/‌​… not that cheap but looks ok.

Perfect! Job done!

what type of diode is that in series with the supply and batteries?

Pretty much any schottky diode would do. Do you prefer SMD or though-hole?

Hello

Through hole would be easier...is that a new symbol for a diode?

The symbol is different for shottky diode as opposed to "normal" silicon diode.

ok, thanks

RA13V1TB

looks ideal for you

1N5817 is more common

excellent, thank you

you are welcome!

would you need a diode across the relay? or is that only when connecting to transistors?

Oh! Yes. I'll edit.