Elenco Understanding Logic Gates and Circuits - Manual (Page 11)

U
1
8
Project 4: NAND Gate
This circuit demonstrates how the NAND
Gate (U18) 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
either input A OR input B are low (0), then
the Q output on U18 will be high (1), and the
red LED (D1) will be on. The output logic is
exactly the opposite of the AND gate, hence
this gate is called the
NOT AND or NAND
Gate.
NAND gates are used in digital logic circuits to perform an inverted logical multiply. When one of the
inputs is low (0), the output is high. The output will only be low (0) when both inputs are high.
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 1
1 0 1
1 1 0
11
2
2
1
3
2
A
B
Q