Simple Item Detector

A simple item detector that detects a single type of item (gold nugget as shown here).
It uses a RSNor Latch, a pulse length detector, and a few tripwires.
If the item in incorrect it will pass the bunch of chosen item on its route and activate the last tripwire, shortening the pulse. But if the item is correct it won't activate the last tripwire (by stopping at the bunch), and thus letting the pulse go all the way. This is not the most compact or reliable, but its completely original, so please give me credit!