10.1 Boolean Logic

Standard Logic Gates

The 6 Gates You Must Know

In the 0478 syllabus, you must recognize the symbols and truth tables for:

  • NOT: Reverses the input.
  • AND: Output 1 only if BOTH inputs are 1.
  • OR: Output 1 if AT LEAST one input is 1.
  • NAND: NOT AND (Opposite of AND).
  • NOR: NOT OR (Opposite of OR).
  • XOR: Output 1 only if inputs are DIFFERENT.
Concept Diagram
Figure 10.1.1: Standard Logic Gates

Logic Expressions

Converting Diagrams to Algebra

Logic circuits can be written as expressions, for example:

X = (A AND B) OR (NOT C)

Concept Diagram
Figure 10.1.2: Logic Expressions

Lab Task 1: Industrial Safety

Task: Industrial Press Safety

A heavy industrial press should only operate if the operator has BOTH hands on buttons.

Lab Task 2: Home Alarm

Task: Intruder Alert

An alarm should sound if the Master Switch is ON AND (either the Window OR the Door sensor is triggered).

  1. Create 3 inputs: Master_Sw, Window, and Door.
  2. Combine them using an OR and an AND gate.
  3. Export your completed circuit image.