Elenco Understanding Logic Gates and Circuits - Manual (Page 12)

U
1
9
Project 5: NOR Gate
This circuit demonstrates how the NOR Gate
(U19) works. Turn the slide switch (S1) on.
Connect the loose ends of the red and black
wires to either low voltage (denoted as a
“0”) or high voltage (denoted as a “1”). If,
and only if, both input A AND input B are
low (0), then the Q output on U19 will be
high (1), and the red LED (D1) will be on.
The output logic is exactly the opposite of
the OR gate, hence this gate is called the
NOT OR or NOR Gate.
NOR gates are used in digital logic circuits to perform an inverted logical add. When one of the inputs is
high (1), the output is low. The output will only be high (1) when both inputs are low.
1
0
1
1
1
1 1
2
2
2
2
2
3
3
2
A
Q
B
Input (A) Input (B) Output (Q)
0 0 1
0 1 0
1 0 0
1 1 0
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2
2
3
1
2
A
B
Q