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 ...

People often ask me about connections between logic devices and industrial electronic sensors. Manufacturers of sensors often specify outputs as either “NPN” or “PNP.” Electrical engineers understand ...

[Dr. Cockroach]’s goal was to build a four-bit computer out of recycled and repurposed junk. The resulting computer, called IO, consists of a single 555, around 230 PNP and NPN transistors, 230 diodes ...