Sound Stop Game
Electronic
7400, 7476

Here's another circuit that will let you see how well you can anticipate whether a digital circuit will be 0 or 1. If you guess right, you can turn off the sound from the Speaker.

You'll notice that this Project uses two multivibrators. The transistor multivibrator produces the pulses you hear from the Speaker. It is turned off and on by the pulses from the NAND gate multivibrator.

The J-K flip-flop plays an important part in the circuit ... can you guess why?

You change the output of the J-K flip-flop by pressing the Key. If the output at Q is 1, the sound will not stop. If the output is 0, the sound stops.

To play this game, turn the power to ON and you'll hear a sound from the Speaker.

Press the Key. Does the sound stop?

If not, try pressing the Key again and again until you finally manage to turn off the sound.

After you play the game a few times, you might suspect that there is some sort of pattern to pressing the Key at the right moment to stop the sound.

Keep careful notes of when you press the Key and what happens — try using a clock or watch with a second hand to make your notes as accurate as possible.

Is there really a pattern?