The NPN transistor as a circuit element NPNTransistors

The NPN transistor as a circuit element

NPN-Transistors Replace Mechanical Switches “Tin Can” Collector Base Emitter

NPN-Transistors are constructed differently and this fact is reflected in the names that are given to the pins. As a first pass at this technology, it will not hurt to associate the names in pairs. The 1960’s transistor However, ultimately the operational principles for the pins with similar names is not the same for different types of transistors. The “Tin Can” it isn’t tin and it isn’t a can! Base OR Gate Emitter OR Source Collector OR Drain

NPN-Transistor Bipolar Junction Transistor Silicon structure with a shortage of electrons in its structure p-type material Bas e Silicon structure with extra electrons in its structure Co lle c tor n p n Silicon structure with extra electrons in its structure Emitter n-type material

NPN-Transistor Ground connection This switch now controls the light. Bipolar Junction Transistor If it is closed, the light will go on. If this switch is closed, the light will turn on if the switch in the base circuit is closed. Simple Switching Circuit Example Collector Emitter n negative terminal positive terminal p n Ba se Ground connection

NPN-Transistor Ground connection Bipolar Junction Transistor Simple Switching Circuit Example Collector electron flow Emitter negative terminal positive terminal Ba se Ground connection

NPN-Transistor Ground connection Another view of the npn transistor switch circuit positive terminal Ba se Collector Emitter Ground connection negative terminal Ground connection

NPN-Transistor Ground connection positive terminal se Collector Emitter Ground connection negative terminal Ba This new cartoon is a little closer to reality since it includes a drawing of a real npn transistor with its correct pin locations. NTE 198 Ground connection Ba Em itt er se lle Co or ct Ground connection Notice that the base connection is not in the middle of the device package even though inside the package the base is in the middle of the device. Negative terminal positive terminal Ground connection

NPN-Transistor Base Negative terminal Collector Emitter r mi tte Ba se E Ground connection NTE 198 positive terminal

NPN-Transistor Base Negative terminal Collector Emitter positive terminal Ground connection

Base Negative terminal Collector Emitter positive terminal Ground connection