35 lines
1.4 KiB
Markdown
35 lines
1.4 KiB
Markdown
|
---
|
||
|
|
tags:
|
||
|
|
- Logic
|
||
|
|
- Electronics
|
||
|
|
- Hardware
|
||
|
|
- logic-gates
|
||
|
|
---
|
||
|
|
# NOT gate
|
||
|
|
|
||
|
|
This gate corresponds to the `NOT` Boolean or negation logical connective. It is really simple and derived from the trivial logical fact that `true` is `true` and `false` is `false` also known as **logical identity**.
|
||
|
|
|
||
|
|
### Natural language
|
||
|
|
>
|
||
|
|
> The negation operator (`¬` or `~` ) switches the value of a proposition from `true` to `false`. When we put `~` before `true` it becomes `false` and when we put `~` before `false` it becomes `true` .
|
||
|
|
|
||
|
|
### Truth table
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
This corresponds to a simple on-off switch.
|
||
|
|
|
||
|
|
In terms of logic gates we would create this by using a single NAND gate. Although it can take a total of two inputs, it would be controlled by a single switch, so both inputs would be set to `1 1` or `0 0` when the switch is activated and deactivated. This would remove the `AND` aspect of `NAND` and reduce it to `NOT` .
|
||
|
|
|
||
|
|
A NAND gate simulating NOT logic
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
TO DO: Come back to this with new book and explain better how a NAND can be reduced to NOT.
|
||
|
|
|
||
|
|
### Symbol for `NOT` gate
|
||
|
|
|
||
|
|
NOT has its own electrical symbol to distinguish it from a NAND:
|
||
|
|
|
||
|
|
|