LOGIC GATES
Lesson Objectives:
• To understand the function of Logic Gates
A logic gate is a digital circuit which either allows a
signal to pass through it or to stop it.
There are three basic log...
OR GATE
INPUT

A
X

INPUT

OUTPUT

B

The output will be positive (True) if at least one input is true.
OR GATE
ON/OFF
Front Doorbell Switch
Doorbell
Back Doorbell Switch
ON/OFF

ON/OFF

If either the Front Doorbell Switch
OR ...
AND GATE
INPUT

A
X

INPUT

OUTPUT

B

The output will be positive (true) when both inputs (the input one AND the input tw...
AND GATE
ON/OFF
Person Sensor
Burglar Alarm
Alarm Switch
ON/OFF

If both the Person Sensor AND
the Alarm Switch are on the...
NOT GATE
INPUT

A

X

OUTPUT

A NOT gate (inverter) has only one input. It reverses the logic state.
NOT GATE
Temperature Detector
(Above 20°C)

Central Heating

ON/OFF

ON/OFF

If the temperature is above 20°C
then the Cen...
Upcoming SlideShare
Loading in …5
×

Logic Gates Presentation

19,100 views

Published on

Published in: Education, Technology, Business
  • Be the first to comment

Logic Gates Presentation

  1. 1. LOGIC GATES Lesson Objectives: • To understand the function of Logic Gates
  2. 2. A logic gate is a digital circuit which either allows a signal to pass through it or to stop it. There are three basic logic gates: AND, OR and NOT. AND GATE OR GATE NOT GATE
  3. 3. OR GATE INPUT A X INPUT OUTPUT B The output will be positive (True) if at least one input is true.
  4. 4. OR GATE ON/OFF Front Doorbell Switch Doorbell Back Doorbell Switch ON/OFF ON/OFF If either the Front Doorbell Switch OR the Back Doorbell Switch is pressed then the Doorbell rings.
  5. 5. AND GATE INPUT A X INPUT OUTPUT B The output will be positive (true) when both inputs (the input one AND the input two) are positive (true).
  6. 6. AND GATE ON/OFF Person Sensor Burglar Alarm Alarm Switch ON/OFF If both the Person Sensor AND the Alarm Switch are on then the Burglar Alarm is activated. ON/OFF
  7. 7. NOT GATE INPUT A X OUTPUT A NOT gate (inverter) has only one input. It reverses the logic state.
  8. 8. NOT GATE Temperature Detector (Above 20°C) Central Heating ON/OFF ON/OFF If the temperature is above 20°C then the Central Heating is switched off. If the temperature is below 20°C then the Central Heating is switched on.

×