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.

It offers both normally open and normally closed outputs and automatically detects the kind of load connected to see if the load needs an npn or pnp output. A four-in-one sensor operates in any of ...

An NPN sensor is a ‘sinking’ sensor because it sinks the output to ground whereas a PNP sensor is a ‘sourcing’ sensor because it provides positive voltage to the output. Below you can see the standard ...

The Bipolar Junction Transistor (BJT, such as NPN and PNP) was developed soon after the point-contact transistor which was developed at Bell Labs in 1947.

Just like with NPN and PNP transistors, there are N-FETs and P-FETs. N-FETs are like NPN transistors – the gate pin needs to have higher voltage than the source pin for the FET to open.