Elenco Understanding Logic Gates and Circuits - Manual (Page 8)

Project 1: NOT Gate (Inverter)
A Q
Input (A) Output (Q)
0 1
1 0
U
1
5
This circuit demonstrates how the NOT
Gate (U15) works. Turn the slide switch
(S1) on. Connect the loose end of the
red wire to either low voltage (denoted
as a “0”) or high voltage (denoted as
“1”). If input A is low (0), then the Q
output will be high (1), and the red LED
(D1) will be on. If input A is high (1),
then the Q output will be low (0) and
the red LED will be off.
1
0
NOT gates are used in digital logic circuits to “invert a voltage level”. A high voltage level (1)
into the NOT gate becomes a low voltage level (0) at the output and vice versa.
1
1
1
1 1
2
2
2
2
2
3
3
The inversion of a state is often
represented
with a bar over the
variable, so Q = A .
8
1
2
3
2
2
A
Q