Among the many methods available for air flow detection, self-heated thermal flow sensors are simple, cheap, rugged, and sensitive. They rely on the relationship between airspeed (AF) and thermal ...

Manufacturing companies, particularly those that mass-produce electronic circuits, work pretty much around bipolar junction transistors, like PNP and NPN. However, choosing between these two BJTs ...

Like an NPN transistor, a PNP can operate in saturation, linear operation, ... As you might expect, current has to flow through that diode junction to turn the transistor on.

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 “backwa… ...

The transistors used (a 2N3055 npn and 2N2955 pnp in TO-220 packages) are reasonably good choices. They should be placed on a heat sink for good heat dissipation.

Sourcing power means the sensor output supplies a positive voltage when the sensor turns on. This is called a pnp output. The name comes from the pnp output transistors used to control the power.

There are numerous differences between NPN and PNP transistors, and even though both are bipolar junction transistors, the direction of current flow is the name of the game.

This paper presents the first process to allow the embedding of amorphous silicon thin film transistors in surface micromachined polymerMEMS. The presented polymerMEMs fabrication technique embeds ...

Transistor Flow Control. Forget valves--controlling fluids with electric fields. By Charles Q. Choi. Join Our Community of Science Lovers! Sign Up for Our Free Daily Newsletter. Enter your email.