This AND That

Project Number: 48

OBJECTIVE: To introduce you to digital circuits.

Description: Build the circuit shown. Notice that if you turn on the slide switch (S1) AND press the press switch (S2) the LED (D1) lights up. Once again, there is no partially lit here, the LED is totally on or totally off. Two switches like this may be used to turn on the same light in your house, the room and the master switch in your electrical box. You could also have more than two switches and the circuit would function the same way. Combinations of AND and OR circuits are used to add and multiply numbers together in modern computers. These circuits are made of tiny transistors in massive integrated circuits.