Transistors

Transistors

Transistor

Page issues
For other uses, see Transistor (disambiguation).
Assorted discrete transistors. Packages in order from top to bottom: TO-3, TO-126, TO-92,SOT-23.
A transistor is a semiconductor device used to amplify or switch electronic signals andelectrical power. It is composed ofsemiconductor material usually with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits.
The transistor is the fundamental building block of modern electronic devices, and is ubiquitous in modern electronic systems.Julius Edgar Lilienfeld patented a field-effect transistor in 1926[1] but it was not possible to actually construct a working device at that time. The first practically implemented device was a point-contact transistor invented in 1947 by American physicists John Bardeen,Walter Brattain, and William Shockley. The transistor revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, andcomputers, among other things. The transistor is on the list of IEEE milestones in electronics,[2] and Bardeen, Brattain, and Shockley shared the 1956 Nobel Prize in Physics for their achievement.[3]


  BN junction diode


Bipolar junction transistor

"Junction transistor" redirects here. For other uses, see Junction transistor (disambiguation).
"BJT" redirects here. For the Japanese language proficiency test, see Business Japanese Proficiency Test. For Beijing Time, see China Standard Time.
BJT NPN symbol (case).svgNPN
BJT PNP symbol (case).svgPNP
BJT schematic symbols
Typical individual BJT packages. From top to bottom: TO-3, TO-126, TO-92,SOT-23
A bipolar junction transistor (bipolar transistor or BJT) is a type of transistor that uses both electron and hole charge carriers. In contrast, unipolar transistors, such as field-effect transistors, only use one kind of charge carrier. For their operation, BJTs use two junctions between two semiconductor types, n-type and p-type.
BJTs are manufactured in two types, NPN and PNP, and are available as individual components, or fabricated in integrated circuits, often in large numbers. The basic function of a BJT is to amplify current. This allows BJTs to be used as amplifiers or switches, giving them wide applicability in electronic equipment, including computers, televisions, mobile phones, audio amplifiers, industrial control, and radio transmitters.

Comments

Post a Comment

Popular posts from this blog

CA

Image
Edit Watch this page Read in another language Institute of Chartered Accountants of India The Institute of Chartered Accountants of India  ( ICAI ) is the national  professional accounting body  of  India . It was established on 1 July 1949 as a  statutory body  under the Chartered Accountants Act, 1949  enacted by the  Parliament  (acting as the provisional Parliament of India ) to regulate the profession of  Chartered Accountancy  in India. ICAI is the second largest professional Accounting & Finance body in the world. However, the rapid growth and autonomy of the ACCA in the early 2000s, soon made ICAI the third largest in terms of membership, the first being the ACCA. ICAI is the only licensing cum regulating body  of the  financial audit  and accountancy  profession in India. It recommends the  accounting standards  to be followed by companies in India to  National Advisor...
Read more

Telecommunication

Image
Edit Watch this page Read in another language Telecommunication Not to be confused with   Teleconnection . Earth station   at the satellite communication facility in Raisting, Bavaria, Germany Visualization from the   Opte Project   of the various routes through a portion of the Internet Telecommunication   is the   transmission   of signs, signals, messages, words, writings, images and sounds or information of any nature by   wire ,   radio , optical or other electromagnetic   systems. [1] [2] Telecommunication occurs when the exchange of   information   between communication   participants includes the use of   technology . It is transmitted either electrically over physical media, such as cables , or via   electromagnetic radiation . [3] [4] [5] [6] [7] [8]   Such transmission paths are often divided into   communication channels   which afford the advantages of mult...
Read more

Local aria network

LAN A conceptual diagram of a local area network. "LAN" redirects here. For other uses, see   LAN (disambiguation) . A   local area network   ( LAN ) is a   computer network   that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. [1]   By contrast, a   wide area network (WAN) not only covers a larger geographic distance, but also generally involves   leased telecommunication circuits . Ethernet   and   Wi-Fi   are the two most common technologies in use for local area networks. Historical technologies include   ARCNET , Token ring , and   AppleTalk . History Cabling Edit Early LAN cabling had generally been based on various grades of   coaxial cable . Shielded twisted pair   was used in IBM's   Token Ring LAN implementation, but in 1984,   StarLAN showed the potential of simple   unshielded twis...
Read more