Using the NOR gate
Électronique / Electronic

Here's another circuit that gives you a clue to how it works by its name. Think you can figure it out?

Try and see how close you come!

As you build this Project, make sure the Select Switch is set to B. Turn the Power Switch to ON, What does LED 1 do?

Now press the Key. Is there any change in LED 1?

Release the Key and set the Select Switch to A. What happens now?

Now press the Key again while the Select Switch is at A. Is there any change in LED 1 ?

As you can see, a NOR gate does the opposite of what art OR gate does. A NOR gate normally has an output (or, as electronics engineers like to say, it's at 1).

But whenever one or both inputs are activated? the output goes off (or becomes 0).

Now think a second ... what does this NOR gate remind you of?

We hope you said Project An inverter circuit, where we met the inverter circuit.

You can see that a NOR gate is really an inverter circuit with more than one input. If all of the inputs are 0: the output is 1. But if any of the inputs are 1, then the output becomes 0.

Where'd you suppose they came up with this name from? How about "not' "or" (or in other words an inverted OR). Can you think of how NOR circuits could be used in electronic devices?