AND circuit with three inputs
In Project AND gate we first met the AND circuit. That one just had two inputs. Think that an AND circuit, like an OR circuit, could have more than just two inputs?
Here's a Project that will let us find out. Before making any wiring connections, Put the Select Switch to B. After building the circuit, press the Key. What happens?
Release the Key put the power ON. Do you see any results?
Put the power OFF and set the Select Switch to A. Do you see anything happening?
Now put the power ON and the Select Switch to A. Press the Key and look at LED 1. What do you see?
This Project again shows that an AND circuit is one whose output is 1 if (and only if) all inputs are also 1. And you can see that an AND gate can have more than two inputs.
The 74HC30N IC have 8 input !