truth tables and gate input 1input 2 00 10 01 11 output 0 0 0 1 ? ? ? ? input 1input 2 00 10 01 11...
TRANSCRIPT
Truth tables
AND Gate
Input 1 Input 2
0 0
1 0
0 1
1 1
output
0
0
0
1
output
?
?
?
?
Input 1 Input 2
0 0
1 0
0 1
1 1
output
?
?
?
?
output
0
1
1
1
OR Gate
Truth tables
NAND Gate
Input 1 Input 2
0 0
1 0
0 1
1 1
output
1
1
1
0
output
?
?
?
?
Input 1 Input 2
0 0
1 0
0 1
1 1
output
?
?
?
?
output
1
0
0
0
NOR Gate
INPUT PROCESS OUTPUT
Thermister LOGIC
GATES
Buzzer
LDR Bulb
Switch
PARTS OF A SYSTEM
Simple system – Alarm when it is hot and a window is closed
Push SwitchDown = ?
Up = ?
Thermister
Hot = ?
Cold = ?
Down = 1
Up = 0
Hot = 1
Cold = 0
Gate? Buzzer
Simple system – Alarm when it is COLD and a window is closed
Push Switch
Thermister
Down = 1
Up = 0
Hot = 1
Cold = 0
Gate?
Buzzer
The most complicated diagram you could be asked
Thermister
On/off Switch
LDR
Light a bulb when it is HOT and DARK and a swtich is turned on
Hot = 1
Cold = 0
Light = 1
On = 1
Dark = 0
off = 0
First step?
Second step?
Last step?
The Bistable or Latch gate
You are only ever expected to say how it works like this:
1. When SET becomes on the output switches ON……..
SET
RESET
output
2. Even if SET becomes off the output stays ON
3. If the RESET becomes on the output becomes OFF