A Dice Circuit Using LED

This is a design circuit for a game a dice. This circuit uses 7 LED to simulate the rolling of a dice after the Roll button is pushed. It has a slowdown feature so that you can see the rolling of the dice slowing down and then stop. This is more satisfying than the usual LED dice circuit which just stops after the button is released. This circuit is work with based on 555 IC and 14017. IC 14017 is decade counter. This is the circuit figure.


The principle work of the circuit is when the switch is turned on Q4 is turned off (its base is pulled high by the 3.3M ohm resistor) and the 555 oscillator is not oscillating. Pressing the ROLL switch immediately charges the 470nF capacitor, Q4 is turned ON and the 555 starts to oscillate. The 470nF gradually discharges via the 10M ohm and 3.3M ohm resistors and turns Q4 off. The 555 is connected as an oscillator. The frequency of oscillation is generally independent of the potential difference across the pins. However, as Q4 turns off the frequency becomes dependent on the voltage. The counter CP0 is advanced by a LOW to HIGH transition from pin 3 of the 555 to pin 14. The first six outputs from the 14017 labeled are labeled by O0 to O5. The next output O6 from pin 5 is connected to the Reset pin 15.