I do not understand how to hook this up exactly. I know the - + at the top connect to laser diode but don't I need a negative input from the battery somewhere? I tried to using + but it didn't work? What am I doing wrong...
So I bought this and I have looked around the forums and have had no luck in figuring out what is - and what is + to hook the battery to. I know how wire the diode just not power input.