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 ...

Matching a sensor interface with a programmable logic converter or controller hardware that can accept only one type of input—npn or pnp—can be difficult. The last-stage modification circuit described ...

Certain types of discrete transistors, the NPN 2N2222 and the PNP 2N2907, can be operated as inverted mode switches where “inverted” means that the collector is made to serve as an emitter and the ...