Light or sound
Electronic
7476

Flip-flop circuits can be used in game circuits since there's no way to tell if the flip-flop circuit is set or reset just by looking at it. Trying to outwit a flip-flop circuit can be frustrating ... as this Project will demonstrate.

You can see how this circuit works by looking at the schematic. You set or reset the flip-flop using the first Select Switch.

The Q- and Q outputs are selected by the second Select Switch. Depending on whether the two outputs are 0 or 1, either LED 1 will light or the audio oscillator will sound when the Key is pressed.

To play with this circuit, set the Select Switch to either A or B as you build it, When you finish, turn the power ON.

Select A or B of the first Select Switch. Now set the second Select Switch to either A or B.

Press the Key — what happens?

You either got a sound from the Speaker or LED 1 lit. Continue to hold the Key down and select the second position of the second Select Switch.

You'll see the opposite now happen — if the LED is lit, it will go out and you'll hear a sound from the Speaker. This shouldn't too much of a surprise to you ... as you can see on the schematic, terminal S is the set input and terminal R is the reset input.

You can use this Project as a game by selecting S or R and then trying to figure out whether the LED will light or a sound will come from the Speaker.

What are the combinations of Q- and Q levels (0 or 1) and Select Switch positions to let each happen?