OR logic using NAND gates

OR logic is a basic digital logic. There is a specific gate for this logic, the OR gate. An OR gate gives a digital HI as output while even just one of its input is HI. The result of the project is digital circuit using NAND gates that implement the OR logic. A LED turns on only while even one of the two buttons is pressed.


The project is an introduction to digital circuits.

  • You see how breadboards, resistors, push buttons, ICs and LEDs look like.
  • You understand how breadboard works.
  • You understand the difference between schematic and real circuit.
  • You understand the difference between digital logic and digital gates.
  • You can notice a way to create digital HI/LO signal.
  • You understand the OR logic.

The Schematic

This is the circuit of the project.project-OR-logic-with-NAND-gates-schematic-2

On breadboard


You can see a way to set up the circuit on the breadboard. Remember, there are many correct ways to transfer a circuit on the breadboard.


  • The NAND gate is called universal gate because using only NAND gates is possible to get any digital function.