Here it is illustrated how the 74S02 quad two input NOR gate logic gate works, how to build and test it on breadboard. Also is shown with Proteus simulation how the 72S02 quad 2-input NOR gate logic operates. For NAND logic gate implementation and operation see the 74ALS00AN NAND gate Implementation & Simulation tutorial.
NOR Gate
NOR gate represents the complement of the OR logic gate. NOR gates alone can implement any Boolean function and it is called universal logic gate.
74S02 NOR gate on Breadboard & Circuit Diagram
The following picture shows 74S02 NOR gate circuit diagram with two inputs using push buttons and output using a LED.
The following shows the 74S02 NOR logic gate circuit diagram with two inputs using push buttons and output using a LED implemented on the breadboard above.
The two inputs to the first NOR gate in the 74S02 IC(Integrated Circuit) is provided using two push buttons. The two push buttons are connected via pullup resistor of 10KOhm on the input side and grounded on the other side of the push buttons. The output of the NOR logic gate is connected to a LED.
74S02 quad 2-input NOR gate IC
The following picture shows DIP(Dual In-Line Package) 74S02 quad 2-input NOR gate integrated circuit(IC).
The 74S02 quad 2-input NOR gate IC is a 14 pin IC which has internally 4 independent NOR logic gate. The pin out of the 74S02 quad 2-input NOR gate IC is below.
The pin 7 is the ground and the pin 14 is Vcc. The Vcc pin is connected to +5V regulated supply and the ground pin 7 is connected to ground of the supply. The rest are 4 NOR gate with the first NOR logic gate occupying the pins A1, B1(the inputs) and Y1(the output). In this tutorial we will only use the first NOR logic gate.
The truth table of the 72S02 NOR logic gate is below.
In the above circuit diagram of implementing the NOR gate on breadboard. The initial state of the two inputs are HIGH(H) because the input is pulled up using pull up resistors. So when both the push buttons are pressed and both gets grounded then the LED will turn ON because the output with both low inputs the output is HIGH. Otherwise, for the other 3 condition in the truth table the LED will be OFF.
74S02 Two Input NOR Gate Simulation
The following video demonstrates Proteus simulation of how the 74S02 2-input NOR logic gate works.
74S02 Two Input NOR Gate on Breadboard
The following video shows demonstration of how the 72S02 two input NOR logic gate works on breadboard.
So in this digital electronics tutorial it was shown how one can build and test NOR gate on a breadboard and how to perform NOR gate simulation in Proteus. For the NOR logic gate the 74S02 quad 2-input NOR logic gate was used. Two push buttons were used as input and a LED was used for output.
