Introduction
The Sloth is waiting for you on the mountain:
“I want total silence: the output only turns on when no trail has light.
Let’s use OR to detect if there’s light, and NOT to invert.”
Logical goal
The output should be 1 only if A = 0 and B = 0:
See full truth table
| A | B | A OR B | Output = NOT(A OR B) |
|---|---|---|---|
| 0 | 0 | 0 | 1 |
| 0 | 1 | 1 | 0 |
| 1 | 0 | 1 | 0 |
| 1 | 1 | 1 | 0 |
Simulator instructions
1. Place
- Inputs: A, B
- OR Gate
- NOT Gate
- Output
2. Connect
- A and B ➔ OR
- OR output ➔ NOT
- NOT output ➔ Output
3. Test
- Try 00, 01, 10, 11.
- Only with 00 should the output be 1.
Victory condition: if there is any light in A or B, the output is 0.
Quick tips
- If the output always stays at 1, the cable from OR to NOT may be missing.
- Name the intermediate signal
OR_AB.
Simulator
What did you learn?
- How to express “none of the inputs are active” with OR followed by NOT.