Even though they are simple, they are the most important electrical component. For example, transistors are almost the only components used to build a Pentium processor. A single Pentium has about 3.5 million transistors. The ones in the Pentium are smaller than the ones we will use but they work the same way. Sometimes they are labeled on the flat side of the transistor.
Transistors always have one round side and one flat side.
If the round side is facing you, the Collector leg is on the left, the Base leg is in the middle, and the Emitter leg is on the right. If there is no current flowing to the Base, then no current can flow from the Collector to the Emitter. Below is the basic circuit we will use for all of our transistors. To put the transistor in the breadboard, seperate the legs slightly and place it on the breadboard so each leg is in a different row. Next move the jumper wire going from ground to the 330 ohm resistor to the Emitter of the Transistor.