# OR Gate – Logic Gates Tutorial

An OR gate is a logic gate the place the output goes HIGH (or “1”) if any of its inputs are HIGH. So if A OR B is HIGH, the output Q additionally turns into HIGH.

The logic or Boolean expression for an OR gate is which implies:

If A or B is true, then Q is true

## Reality Desk

OR gates can have greater than two inputs. However irrespective of what number of inputs it has, it’s going to at all times give out a HIGH or logic “1” if certainly one of its inputs is HIGH.

## IC Options with OR Gates

If you wish to experiment and construct circuits with OR gates, you’ll discover them in each the 4000 IC sequence and the 7400 IC sequence:

• 4071: 4 2-input OR gates
• 4075: Three 3-input OR gates
• 74HC32: 4 2-input OR gates (HC is the household, may also be LS/HCT/…)
• 74HC4075: Three 3-input OR gates (HC is the household, may also be LS/HCT/…)

These ought to all be out there as hobbyist-friendly through-hole chips. Simply be sure to purchase the DIP bundle model.

## Instance Circuit: Testing an OR gate

Beneath is an easy sensible circuit you possibly can construct to check how this gate works. A Gentle-Emitting Diode (LED) activates whenever you press both of the buttons A OR B. The circuit demonstrates the fundamental operation of an OR gate.

## Subsequent Step within the Logic Gates Tutorial

Take a look at the opposite articles on this logic gates tutorial:

NOT Gate/Inverter
AND Gate
NAND Gate
OR Gate – (You’re right here)
NOR Gate
XOR Gate
XNOR Gate

Again to the Logic Gates Overview