Quote Originally Posted by Marcel View Post
It has been interesting JohnH, and to a fair extent quite enjoyable, and the fun isn't over yet...

About the only thing I can think of Simon that could improve the little light tunnel is maybe a small block of Aluminium with a 5mm hole drilled through. Using Al-foil could be risky in creating short circuits, and anything heavier risks damaging the legs of the LED or LDR. I do have some self-amalgamating tape that I could wrap around, but I think the biggest issue is getting the LED set right to have the greatest affect on the LDR. By my reckoning there needs to be a brighter LED so it's either a new and brighter LED or changing the current limit resistor to a lower value so that the existing LED burns brighter. It would be nice to have a circuit included with the kit so the choice of which way to go would be simpler. Look like I'm going to have to trace the whole thing out the hard way...

I seem to remember reading somewhere that most LDRs (Light Dependent Resistors) tend to have a bell-shaped light-sensitivity curve where they are most sensitive to green light, so, maybe using a Green Led might help things.