Scientific Development Corporation Minivac 601, Getting Acquainted

Page: 12 / 36

EXPERIMENT 4
SERIES CIRCUIT
I his experim ent demonstrates the use of
two pushbuttons connected together in series
to form a c irc u it where both pushbuttons must be
pushed at the same time before the c irc u it is clo sed .
0 Program this c irc u it by making the
follow ing connections: 1+ /1Y 2> y2A
1
V
2
Y
2
B /
2
-
Turn the power switch O N and push down
pushbutton 1 . Watch light 2 . It does N O T
lig h t because the connection from + to
the lig h t is broken by pushbutton
2
.
3
/
Release pushbutton 1 and push down push­
button 2 . Watch light 2 . It still does N O T
lig ht because the connection from + to
the lig h t is now broken by pushbutton
1
.
4 )
Push down both pushbutton 1 and
pushbutton
2
at the same time and see light
2 go O N . A complete c irc u it is now
made through both pushbuttons.
It is possible to connect more than two push­
buttons in series and make a c irc u it where aM the
pushbuttons connected must be pushed down before
the c irc u it is com pleted. Construct a series
c irc u it using three or more pushbuttons by your­
s e lf, to demonstrate this p rin c ip le . The c ir c u it ,
w ith terminal numbers in d ica te d , should first be
drawn on paper. The c irc u it should then be
connected on the computer using programming w ire s.
The c irc u it diagram looks lik e thi
1Z 2 Z
l + *
A - _________
i y i x
v i
A N "A N D " C IR C U IT — The series c ir c u it , where two or more
pushbuttons must A L L be closed to make £ complete c ir c u it , is ca lle d
an A N D c ir c u it , because both pushbutton 1 A N D pushbutton 2 must be closed
before the c irc u it is com plete. This is a basic c irc u it of computer
logic w hich w ill be used la te r.