What is Transistor: Definition and 508 Discussions

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. Transistors are one of the basic building blocks of modern electronics. It is composed of semiconductor 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.
Austro-Hungarian physicist Julius Edgar Lilienfeld proposed the concept of a field-effect transistor in 1926, but it was not possible to actually construct a working device at that time. The first working device to be built was a point-contact transistor invented in 1947 by American physicists John Bardeen and Walter Brattain while working under William Shockley at Bell Labs. The three shared the 1956 Nobel Prize in Physics for their achievement. The most widely used type of transistor is the metal–oxide–semiconductor field-effect transistor (MOSFET), which was invented by Mohamed Atalla and Dawon Kahng at Bell Labs in 1959. Transistors revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, and computers, among other things.
Most transistors are made from very pure silicon, and some from germanium, but certain other semiconductor materials are sometimes used. A transistor may have only one kind of charge carrier, in a field-effect transistor, or may have two kinds of charge carriers in bipolar junction transistor devices. Compared with the vacuum tube, transistors are generally smaller and require less power to operate. Certain vacuum tubes have advantages over transistors at very high operating frequencies or high operating voltages. Many types of transistors are made to standardized specifications by multiple manufacturers.

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    Understanding Lattice Structure & Bipolar Junction Transistor

    trying to figure out the meaning of lattice struction in semiconductor... :yuck: and, why a small current in the base circuit of a transistor can control a large current in collector part when "bipolar junction transmission" happened? Thanks for any help! :confused:
  2. C

    Very low voltage drop transistor

    I'd like to construct a fast-reacting current overload protection device. And rather than use a FET as a short to blow a fuse I'd rather just use a semiconductor in series that I can open on overload. This is similar in operation to some "intelligent circuit breakers" based on a Intra...
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    How exactly does a transistor work?

    For an exhibit I am doing, I have a transistor as a direct implication for quantum mechanics. How exactly does a transistor work? I know it only shuttles in so many electrons, but what does quantum mechanics have to do with it? Paden Roder
  4. B

    Music Formula: Transistor Theory Applied

    Music formula. Check out my transistor 1.) God : Thought : Song Intro, the very first sound. 2.) Food : Word : Song Lyrics, the story if you will. 3.) Neighbour : Deed : Song Chorus describing a concept to a neighbour. Like ants or bees. We eat our fill in the world, then describe the...
  5. D

    Building Circuit w/ 2N3904 Transistor: Can I Use NPN from Science Kit?

    I want to build this circuit http://www.uoguelph.ca/~antoon/circ/fmt1.htm. It requires transistor 2N3904. Is this any NPN transistor or do I have to get a specific one? I have some transistor but it just labeled NPN (from science kit). Can I used that?
  6. C

    Calculating Emitter, Base and Collector Currents in an NPN Transistor

    The emitter current in a certian npn transitor is 8 mA. If .8% of the minority carrier injected into the base recombing with the holes, find the base current , collector current and the exact value of alpha i am not sure how to get this started thanks joe
  7. O

    DNA used to create self-assembling nano transistor

    DNA nano-technology is rapidly coming to a point in which applications for mankind will have enormous implications. It now becomes evident that mankind can manipulate DNA that will eventually change the way we live, our health and the world around us...
  8. B

    Understanding Transistor Concepts: Confusion with R1, R2, and IB

    http://home.netvigator.com/~cyberforce/img/phy.jpg I have learn transistor just few lessons.. For a) what i learn is that R1 and R2 would share Vin that's mean there is p.d. when current flows via R1, R2 thus, Vin = VR1 + VR2 and i am confused if the current flows via them is the same...
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