kind thanks to you all! just the info we looked for and couldnt find! so just to recap although the diagram says 7.2 volts optimum its actualy around 3v optimum? thanks for the feedback circuit diagram that might well be useful
as for the application......... LG is taken with the new CNC mill and obviously i am not letting him near it! so he has cobbled together a contraption from 2 very old and broken inkjet printers and has a kind of cnc machine of his own, he wants to try and make a kind of etch a sketch with a laser! the actual laser will be enclosed and i milled him a heat sink for it. once its mounted on his contraption he wont actualy be able to get to the light as its set around 15mm from the base of his machine. plus he wont be playing with it without me around. i am somewhat dubious with him messing with stuff like this but i am also more than a bit curious as to what we can get this thing he has made to do
if we manage anything i will post some pictures