Elenco Understanding Logic Gates and Circuits - Manual (Page 14)

U17
Project 7: De Morgan’s Law
Negation of Conjunction
This circuit demonstrates De Morgan’s Law of
Negation of Conjunction which states that the
negation
of a conjunction is equivalent to
disjunction of the negations. Turn the slide switch
(S1) on. The green wire on the left connects the A
inputs of the top U15 module and the U16 module
(representing the A input in the diagrams below)
while the green wire on the right connects the B
inputs of the second U15 module and the U16
module (representing the B input in the diagrams
below). Connect the loose ends of the red wire and
the black wire to either high voltage (1) or low
voltage (0).
No matter what combination you
connect, the green LED and red LED will always
either both be on or both be off, demonstrating that
any combination of inputs to the two diagrams
always provides the same outputs.
Negation of Conjunction = Disjunction of Negations.
1
1
4
A
Q
B
=
A
Q
B
Same
U15
U16
U15
U15
1 1
1
1
1
1
1
1
2
2
1
2
2
2
2
2
2
2
2
2
2
2
2
4
2
3
3
2
3
2
3
3
3
2
3
2
2
2
Negation
of
Conjunction
Disjunction
of
Negations
3
3
2
14
1
0
1
1
5
2
2
3
3
4
4
5
2
A
B
Q
Q