Transistors, Other Engineering

Transistors:

The transistor can be a high or low resistance device, hence the name, which is derived from TRANSfer resISTOR. 

It is used in many switching and amplifier circuits where its resistive properties are controlled by small currents. 


The properties of semi-conductor materials, P and N type, were discussed in Module 4.1.1.  A transistor is made up of these materials in the configurations shown in Figure.  The circuit symbols for these transistors are also shown.

381_Transistor construction.png

As can be seen from figure 1, there are two possible types of physical arrangement:

1. The N-P-N transistor, which consists of a thin region of P-type material, sandwiched between two N-type regions.

2. The P-N-P transistor, which consists of a thin region of N-type material, sandwiched between two P-type regions.

The centre region of the device is called the "Base"; one outer region is called the "Emitter", and the other the "Collector".  Although the emitter and collector regions are the same type of extrinsic semiconductor (N-type in N-P-N and P-type in P-N-P), they are constructed and doped differently and are not interchangeable on a practical device.

The circuit symbol for both P-N-P and N-P-N are shows in figure.  The only difference between them is the direction of the arrowhead on the emitter lead.  For either type, the arrowhead indicates the direction of "Conventional" current flow when the base/emitter junction is forward biased (i.e. base +ve with respect to emitter for an N-P-N device, and base -ve relative to emitter for a P-N-P device).

 

Posted Date: 9/14/2012 6:38:48 AM | Location : United States







Related Discussions:- Transistors, Assignment Help, Ask Question on Transistors, Get Answer, Expert's Help, Transistors Discussions

Write discussion on Transistors
Your posts are moderated
Related Questions

Match plate patterns are used where a rapid production of small and accurate castings is desired on a large scale. These patterns find a great favour in machine moulding. Their co

Economic Definition :  Manufacturing increase the value of product. Technological Definition :  Manufacturing is a process which gives required strength, shape and size of t

A trimmed flight condition is perhaps best thought of as an equilibrium condition. The simplest trim condition is straight-and-level flight, in which the forces (weight, propulsive

Explain the drain characteristics of JFET with external bias


Financial Management, Finance This case has been framed in order to test the skills in evaluating a credit request and reaching a correct decision. Perluence International is large

I have senior design this semester and my professor give my this project. could you help me

Q.  With necessary theory explain the formation of spectrum by a plane transmission grating when composite light falls on it OR How does plane diffraction grating for

calculate inventory turnover ratio, when only given current assets $100,000, current liabilities, $25,000 sales $200,000 and quick ratio=1.5