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 ...

The current flow from collector to emitter in the NPN transistor when the positive supply is applied to the base is vital variations between the NPN vs PNP.

This paper describes the nonidealities of temperature sensors based on substrate pnp transistors and shows how their influence can be minimized The effects of series resistance, current-gain variation ...

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.

Choice of P-N junction device Even though a diode can be used to measure temperature, a diode connected PNP or NPN is preferred. The ideality factor of a diode is up to twice as large as a diode ...

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.

There are also certain amplifier configurations that need PNP units. Like an NPN transistor, a PNP can operate in saturation, linear operation, reverse active, or it can be cut off.

The continuous advances in micro- and nanofabrication technologies have inevitably led to major improvements in field-effect transistor (FET) design and architecture, significantly reducing the ...