This is a Project that's a bit different from the last few (Esp tester).
This one too will help you make a decision .... like whether to go to the left or right.
After you finish the wiring connections, turn the power to ON. You'll notice that LED 4 will light up. Now press the Key. You'll see LEDs 1, 2, 3, and 5 light at what seems to be "half brightness".
Now release the Key. What happens?
You saw that only an LED other than LED 4 lit up. Which one was it?
Now press and release the Key.....and try it again.....and again. Does a different LED light up each time or does the same one light up over and over?
You saw that only an LED other than LED 4 lit works by looking at the schematic. You'll notice that LED 4 is a separate circuit of its own, not affected by the rest of the Project. That's why LED 4 stays lit all the time.
The rest of the Project is the multivibrator/counter/decoder arrangement we've seen in other Projects.
Again, can you figure out how the outputs of the flip-flop are combined in the NAND gates to light just one of the LEDs?
Be sure to make a note of your guess. You can also use this Project in games by letting the position of the lit LED determine moves or the winner in a game. The winner could be who- ever can get a LED to light closest to LED 4, for example.