The use of transistors for switching things ON and OFF is a key feature of proper hacking. The ability for bipolar transistors to turn things ON and OFF is one of the less known uses while transistors ...

The two types of standard transistors are PNP and NPN which differs in circuit symbols. The layers of semiconductor material used to make the transistor are denoted by the letters. To keep a straight ...

In the early days, PNP bipolar transistors were common, but the bulk of circuits you see today use NPN transistors. As [Aaron Danner] points out, many people think PNP transistors are “backward” but ...