1. Starter
Write down a list of what your perfect partner would be like. Can include things to do with looks, hobbies and general habits and traits. Include things they must have, must not have and some negotiables

2. LOGIc gates From the syllabus: George Boole, (1815-1864)
• Explain and use the terms digital and analogue
• State that logic gates are circuits containing transistors and other components
• Describe the action of NOT, AND, OR, NAND and NOR gates
• Design and understand simple digital circuits combining several logic gates
• State and use the symbols for logic gates
George Boole,
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About G. Boole:

3. Analogue and Digital
There are two ways of transmitting information – using ANALOGUE signals and DIGITAL signals.

4. Examples of Analogue Devices
Dimmer switches
Vinyl records
Thermometers
Old fashioned watches
Speedometers

5. Digital Signals
Digital signals are coded pulses and have only two values, for example;
ON and OFF
TRUE and FALSE
1 and 0
HIGH and LOW

6. Digital signals are sent as pulses.

7. Morse code is an example of a DIGITAL signal
There are only two signals, or

8. Examples of Digital Devices
CD’s
On/Off switches
Digital clocks
Digital meters

9. Digital signals are much higher quality because they don’t change when they are transmitted like analogue signals do.
Lots more information can be sent using digital signals compared to using analogue signals.

10. logic gates are circuits containing transistors and other components
A logic gate is a digital circuit which either allows a signal to pass through it or to stop it.
logic gates are circuits containing transistors and other components
There are seven basic logic gates: AND, OR, XOR, NOT, NAND, NOR, and XNOR we will be looking at these 5. OR
GATE
AND
GATE
NOT
GATE
NAND
GATE
NOR
GATE
Note that logic gates are not always required because simple logic functions can be performed with switches or diodes:Switches in series (AND function)Switches in parallel (OR function)Combining IC outputs with diodes (OR function)
Did you know?
Logic gates allow the computer to do things such as add, divide, multiply, do simple yes and no reasoning in certain situations along with other things.

11. ON OFF NOT Output Input CENTRAL NOT HEATING
A NOT gate (inverter) has only one input.
It reverses the logic state.
Y = NOT A
NOT
GATE
Input
Output
NOT
GATE
HEAT DETECTOR
(ABOVE 20 C)
CENTRAL
HEATING ON
OFF
NOT gate has only one input. It reverses the logic state.
If the input will be on – the output will be off
If the input will be off –the output will be on.

12. Truth table for a NOT gate
A NOT gate (inverter) has only one input.
It reverses the logic state.
Y = NOT A
Input
Output 1

13. ON/OFF ON/OFF ON /OFF Input Y = A OR B OR Output Input OR
An OR gate can have two or more inputs.
The output will be positive (True) if at least one input is true.
Y = A OR B OR
GATE
Output
Input
ON/OFF
ON/OFF
FRONT DOORBELL
SWITCH OR
GATE
DOORBELL
BACK DOORBELL
SWITCH
ON /OFF
The output is "true" if either or both of the inputs are "true." If both inputs are "false," then the output is "false.”
It is doesn’t matter if one input will be off- the output will be on

14. Truth table for an OR gate
An OR gate can have two or more inputs.
The output will be positive (True) if at least one input is true.
Y = A OR B
Input 1
Input 2
Output 1

15. ON/OFF ON/OFF ON /OFF Input NOR Y = not (A OR B) Output Input
A NOR gate can have two or more inputs.
The output will be Positive (True) if both inputs are negative
Y = not (A OR B)
NOR
GATE
Output
Input
ON/OFF
ON/OFF
Is some one sat in the seat next to you
NOR
GATE
Friend can sit in seat
Are you taking a test
ON /OFF
The output is "true" if either or both of the inputs are "true." If both inputs are "false," then the output is "false.”
It is doesn’t matter if one input will be off- the output will be on

16. Truth table for a NOR gate
A NOR gate can have two or more inputs.
The output will be Positive (True) if both inputs are negative
Y = Not (A OR B)
Input 1
Input 2
Output for OR
Out put for NOR 1
Input 1
Input 2
Not input 1
Not input 2
Out put for OR
Out put for NOR 1

17. ON/OFF ON/OFF ON /OFF Input AND Output Input AND BURGLAR ALARM GATE
An AND gate can have two or more inputs.
The output will be positive (true) when both inputs (the input one AND the input two) are positive (true).
Y = A AND B
Input
AND
GATE
Output
Input
ON/OFF c
ON/OFF
PERSON SENSOR
AND
GATE
BURGLAR ALARM
ON SWITCH
FOR ALARM
The output is "true" when both inputs are "true.” Otherwise, the output is "false."
If one input will be off – the output will be off as well.
ON /OFF

18. Truth table for an AND gate
An AND gate can have two or more inputs.
The output will be positive (true) when both inputs (the input one AND the input two) are positive (true).
Y = A AND B
Input 1
Input 2
Out put 1

19. ON/OFF ON/OFF ON /OFF Input AND Output Input Do they fit
A NAND gate can have two or more inputs.
The output will be positive (true) if any input is negative
Y = Not (A AND B)
Input
AND
GATE
Output
Input
ON/OFF c
ON/OFF
Do they fit
NAND
GATE
Need to buy new shoes
Are they water tight
The output is "true" when both inputs are "true.” Otherwise, the output is "false."
If one input will be off – the output will be off as well.
ON /OFF

20. Truth table for an NAND gate
A NAND gate can have two or more inputs.
The output will be positive (true) if any input is negative
Y = NOT (A and B)
Input 1
Input 2
Output for AND
Out put for NAND 1

21. In your books An example if you can For each type of gate you need
The name of the logic gate
the symbol for the logic gate
A sentence saying what it does
Its truth table
An example if you can

22. To add more sensors to alarm
GATE
AND
BEDROOM
SENSOR
FRONT ROOM
BURGLAR
ALARM
ON SWITCH
FOR ALARM
ON or OFF ?

23. ON OFF Is the Final Output ON (True) or OFF (false) ? OR AND
GATE
AND
NOT ON
OFF
FINAL
OUTPUT
ON ? OFF ?

24. girlfriend/boyfriend Chooser:
Name the logic gates. Test it by answering True or false (Yes or No) for each Input. ? ON
YES,
She/He is OK
Good dancer
Good at sport
Green eyes
Has big ears

25. Design your own girlfriend/boyfriend Chooser
By writing your own things in the Input boxes. You can choose the logic gates you have learnt. Name the logic gates. Test the Chooser by answering Yes or Not ( True or false ). ON
YES,
She/He is OK

26. Test 1: ? ? ? ? ? ? The output is ON or OFF ? 1. 4. ON OFF ON OFF 5.2. ? ON ? ON
OFF 6. ? ON
OFF
1- off, 2- on, 3-off, 4- on, 5-off, 6-on 3. ? ON
OFF
The output is ON or OFF ?

27. Test 2: ? ? ? ? The output is ON or OFF ? 7. 10. OFF ON ON OFF OFF 8.9. ON ? ON
7- on, 8-off, 9-off, 10- on ON ON ON ON
The output is ON or OFF ?