Timed trigger utilizing op amp and RC network. 5RC (R in ohms and C in farads) gives charge time, decreasing and increasing ohms and farads will respectively decrease or increase charge time. Hit switch and watch as the voltage across capacitor / op amp input rises until it reaches 90 percent of Vcc then triggers.
Pretty useful, you could flip a switch knowing it will trigger a set time later. The load in this example is an Led, driven by a transistor.
The capacitor charges through the 47.7k Resistor and the potentiometer acts as a voltage divider ;setting the trigger point.
