Page 107 - The Addams Family (Williams)

Switch Matrix Circuit
COLUMN (example) ROW (example)
5V
CPU Board +12V +12V
CPU Board r-----~
LS 374SC ULN·2B03 4701
L ~
Open H H
Closed L L Off
On
Dedicated Switch Circuit
DEDICATED GROUND (example) ROW (exaf1l)le)
5V
CPU Board +12V
CPU Board
r-----~
L J
Switch
Off
On
A B c
Open
Closed
H
L
H L
L H
The ADDAMS FAMILY 3-5
E
c