Logic Tutorial: Don't Let Go

So you're building some weird game where you want something to happen when a player steps off a button, but not when a player simply steps on it.  I won't judge -- I'm sure there are plenty of non-evil applications for such a thing.

Here's a simple one:

The negate box triggers the bomb upon loading the game, and proceeds to feed it a continuous signal afterward.  Since bombs can only go off once per signal, this bomb won't trigger a second time despite being powered.  But as soon as an unwitting player steps on that pressure plate, that signal ends and ... nothing happens.  The bomb won't trigger after losing power.  So it's safe, right?  Not exactly.  As soon as the player releases the pressure plate, the negate box sends out its signal again and bam!  Bye-bye Birdie!

That is, unless a time trigger or something else kicks in to power the negate box even after the player releases the button, allowing them time enough to run away.

Want something non-explosive?  It turns out that a time trigger with a short delay works just as nicely.

Here, the time trigger is your bomb.  As soon as the game loads, it sends out a signal for the set duration.  Then it stops once the duration expires, despite still receiving power from that pesky negate box.  Just press the button and release it to reset the system, making that time trigger go off again.

Whether you want to build those Hunger Games bomb plates or something more benign to urge players to stay on a button for a certain amount of time, this system might do the trick.