OT: transistors

[lightningfingers]

what do NPN and PNP stand for

[Jay Doyle]

They stand for the layers of doped silicon that make up a bipolar transistor.

N=negative doped
P=Positive doped

Thus "bipolar". Check out any beginner's tutorial on transistors for a better answer.

[R.G.]

They represent the two main types of bipolar transistors.

The word "bipolar" means "of two polarities", and that's how they got named. Bipolar transistors are made from alternating layers of N-type silicon and P-type silicon. There exist only two ways to make a three-layer device out of alternating types - NPN and PNP, and that's why the transistors are called that.

There are four-layer devices (SCR's and thyristors) and single layer devices (MOSFETs) as well as two layer devices like JFETs, but bipolar transistors are the only ones that are identified by being called by the layering.

[Chris Goodson]

NPN=Not Pointing iN

[lightningfingers]

NPN=Not Pointing iN

LMAO ill remember that one