How does NPN and PNP work?

An NPN transistor has a piece of P-type silicon (the base) sandwiched between two pieces of N-type (the collector and emitter). In a PNP transistor, the type of the layers are reversed. NPN and PNP transistors have very similar schematic symbols. The only difference is the direction of the arrow on the emitter.

How does a PNP work?

The PNP transistor is a type of transistor in which one n-type material is doped with two p-type materials. It is a device that is controlled by the current. When a small current flow through the base of the PNP transistor, it turns on. The current in a PNP transistor flows from the emitter to the collector.

Whats the difference between NPN and PNP?

The main difference between the NPN and PNP transistor is, an NPN transistor turns on when the current flows through the base of the transistor. A PNP transistor turns ON, when there is no current at the base of the transistor. In this transistor, the current flows from the emitter (E) to the collector (C).

How does an NPN work?

The NPN transistor is designed to pass electrons from the emitter to the collector (so conventional current flows from collector to emitter). The emitter “emits” electrons into the base, which controls the number of electrons the emitter emits.

What does a PNP transistor do?

PNP transistors are used to source current, i.e. current flows out of the collector. PNP transistors are used as switches. These are used in the amplifying circuits. PNP transistors are used when we need to turnoff something by push a button.

What is NPN junction?

An NPN transistor is the most commonly used bipolar junction transistor, and is constructed by sandwiching a P-type semiconductor between two N-type semiconductors. An NPN transistor has three terminals– a collector, emitter and base. The NPN transistor behaves like two PN junctions diodes connected back to back.