Understanding logic systems is vital to the work of any Electronic Engineer.
The fundamental thing to understand is that electrical systems have two states – they are either on or off. We call these two states High and Low with High meaning ‘on’ and Low meaning ‘off’. This can also be thought of as a binary (2 state) condition with ‘1’ meaning ‘on’ and ‘0’ meaning ‘off’.
When we are looking at logic systems we commonly use a set of electronic systems called ‘Logic Gates’.
There are seven basic logic gates: AND, OR, XOR, NOT, NAND, NOR, and XNOR.
Most logic gates have two inputs and one output.
We are going to look at some simple logic gates here but you are free to explore others should you wish to. It should also be noted that Logic gates can be connected together to perform other functions – you could also explore how to connect logic gates together.
An AND gate is one of the more common logic gates.
AND gates have two inputs and one output – we can simulate an AND gate using two switches as the state basically means that if switch 1 AND switch 2 are on then the output is on. Any other state means that the output is off. See Fig 1 below and see if you can build and test this on a prototype board as in Fig 2.
You can also get XOR Gates which inverts the output. You could build an XOR gate using an IC such as the CD4070BE.