Understanding Logic Gates: AND, OR, NOT

Real-life example of NOT Gate

• turns ON when sensor does NOT detect daylight

• turns OFF when sensor detects motion

• activates when the temperature is above 30 degrees

• deactivates when the button is pressed

OR Gate truth table

• @@0,0 \rightarrow 0@@

• @@0,1 \rightarrow 0@@

• @@1,0 \rightarrow 0@@

• @@1,1 \rightarrow 1@@

AND Gate function

• is 1 only if both inputs are 1

• is 0 if at least one input is 1

• is 1 if at least one input is 0

• is 0 only if both inputs are 0

NOT Gate function

• is the opposite of the input

• is the same as the input

• inverts the output to high

• outputs a constant value

AND Gate truth table

• @@0,0 \rightarrow 0@@

• @@0,1 \rightarrow 1@@

• @@1,0 \rightarrow 1@@

• @@1,1 \rightarrow 1@@

NOT Gate symbol

• with a small circle at the output

• with two inputs and one output

• with a triangle shape

• with a square shape

Boolean expression for AND

• @@A \cdot B@@

• @@A + B@@

• @@A - B@@

• @@A \div B@@

Real-life example of OR Gate

• A single button can ring a bell

• Two buttons can ring a bell

• A light switch that controls multiple lights

• A doorbell that only works with one button

Real-life example of AND Gate

• switches must be ON for a lamp to light

• a single switch controls multiple lamps

• a lamp lights up when any switch is ON

• a lamp turns off when the switch is ON

OR Gate function

• is 1 if at least one input is 1

• is 1 only if all inputs are 1

• is 0 if at least one input is 0

• is 1 if none of the inputs are 1