Logic gates, truth tables and constructing control circuits for real machines

What this note covers

1. Define what true and false mean for each input
2. AND, OR and NOT express different conditions
3. NAND, NOR and XOR require careful output interpretation
4. Construct the truth table with intermediate columns
5. Draw the circuit from the expression’s structure
6. Verify control behaviour against the original requirement
7. Worked control circuit: truth table before gate drawing
8. Worked electrical check: parallel sensors on a series supply resistor

8 sections · 10 key terms & formulas · 6 common mistakes