ok, Thanks for the info, Now let's add the rube goldberg element, and say it was an example of what I am trying to do but I'm actually trying to do something else, that is really hard to explain. I need some way to non-mechanically detect the ball going through the tube... my closest attempts have been a laser tripwire circuit with a photoresistor but I don't really know how to get a logical 0 or 1 solution from that, and I don't like the "easily breakable", or alignment oriented nature of the laser... I would like to use a better, more consistent source of light than a laser, perhaps an IR circuit, but I am not sure how to go about that in an environment such as a tube.