This trigger can be used to catch high speed motion, like a bursting balloon, bullet in flight, etc.
Straight-forward construction and I purchased a few extra components for the hard to find items
that weren't stocked at my local Radio Shack. If anyone is interested, send me an e-mail.
I have reference document, schematic /diagram.
See next image for internal views
Link to article http://www.rit.edu/~andpph/text-cheap-sync.html