Today we will build two circuits that, with the help of two integrated chips and some components, allow us to generate random results.

Both circuits use a CD4011 IC that implements 4 NAND ports with buffer and a CD4017 IC which is a decades counter. When the button is pressed all LEDs are lit. When it is dropped it is lit randomly.

The first circuit has only one of two possible values. The second presents a result in ten possible values.



Bill of materials (BOM)


  • 1x IC CD4011 (U1 e U4)
  • 1x IC CD4017 (U2 e U3)
  • 1x 470pF Electrolytic Capacitor (C1)
  • 2x 4.7K Ohms Resistor (R1 e R3)
  • 1x 1K Ohms Resistor (R2)
  • 1x SPST Button (SW1)
  • 1x 5mm red LED
  • 1x 5mm green LED
  • 1x 9V Battery

In the second circuit it requires another additional 8 LEDs (The color is not very important)

IC/Components Pin-out


Related Content