OR Gate Using NAND Gates Only

Using NAND gates to make an OR gate is a useful trick when you run out of OR gates in your electronics lab. You might think it is crazy, how can you make an OR gate from NAND gates? However it is not so difficult.

NAND gates are one of the most versatile and you can make many other gates out of them. When you join their inputs together, they behave as a NOT gate would. In electronic circuits you will often see the inputs of a NAND gate joined to make a NOT gate, therefore you can also make an OR function using two NOT gates and a NAND gate.