Skip to content

Unexplainable.net

Watching The World Change

  • Physics at the Edge of the Universe Information and Theories
  • Traditional Holidays on Ancient Chinese Calendar IV Ancient Civilizations
  • Bob Dylan Just Celebrated a Birthday & Still Going Strong”¦Thanks to the Devil? Information and Theories
  • Man Selected to Hold Key to Internet Technology Articles
  • Highlights of Ancient Greek History: 469 BCE to 404 BCE Ancient Civilizations
  • Time Information and Theories
  • Mesopotamian Gods and Goddesses Part 6 Ancient Civilizations
  • 7 Wonders of the Ancient World: Pyramid & Temple Ancient Civilizations

Modern Transistors

Posted on December 6, 2005 By jim No Comments on Modern Transistors

HTML clipboard

In 1945, Shockley had an idea for making a solid state device out of
semiconductors. He reasoned that a strong electrical field could cause the flow
of electricity within a nearby semiconductor. He tried to build one, then had
Walter Brattain try to build it, but it didn’t work.

Three years later, Brattain and Bardeen built the first working transistor, the
germanium point-contact transistor, which was manufactured as the “A” series.
Shockley then designed the junction (sandwich) transistor, which was
manufactured for several years afterwards. But in 1960 Bell scientist John
Atalla developed a new design based on Shockley’s original field-effect
theories. By the late 1960s, manufacturers converted from junction type
integrated circuits to field effect devices. Today, most transistors are
field-effect transistors. You are using millions of them now.

Most of today’s transistors are “MOS-FETs”, or Metal Oxide Semiconductor Field
Effect Transistors. They were developed mainly by Bell Labs, Fairchild
Semiconductor, and hundreds of Silicon Valley, Japanese and other electronics
companies.

Field-effect transistors are so named because a weak electrical signal coming in
through one electrode creates an electrical field through the rest of the
transistor. This field flips from positive to negative when the incoming signal
does, and controls a second current traveling through the rest of the
transistor. The field modulates the second current to mimic the first one — but
it can be substantially larger.

On the bottom of the transistor is a U-shaped section (though it’s flatter than
a true “U”) of N-type semiconductor with an excess of electrons. In the center
of the U is a section known as the “base” made of P-type (positively charged)
semiconductor with too few electrons. (Actually, the N- and P-types can be
reversed and the device will work in exactly the same way, except that holes,
not electrons, would cause the current.)

Three electrodes are attached to the top of this semiconductor crystal: one to
the middle positive section and one to each arm of the U. By applying a voltage
to the electrodes on the U, current will flow through it. The side where the
electrons come in is known as the source, and the side where the electrons come
out is called the drain.

If nothing else happens, current will flow from one side to the other. Due to
the way electrons behave at the junction between N- and P-type semiconductors,
however, the current won’t flow particularly close to the base. It travels only
through a thin channel down the middle of the U.

There’s also an electrode attached to the base, a wedge of P-type semiconductor
in the middle, separated from the rest of the transistor by a thin layer of
metal-oxide such as silicon dioxide (which plays the role of an insulator). This
electrode is called the “gate.” The weak electrical signal we’d like to amplify
is fed through the gate. If the charge coming through the gate is negative, it
adds more electrons to the base. Since electrons repel each other, the electrons
in the U move as far away from the base as possible. This creates a depletion
zone around the base � a whole area where electrons cannot travel. The channel
down the middle of the U through which current can flow becomes even thinner.
Add enough negative charge to the base and the channel will pinch off
completely, stopping all current. It’s like stepping on a garden hose to stop
the flow of water. (Earlier transistors controlled this depletion zone by making
use of how electrons move when two semiconductor slabs are put next to each
other, creating what is known as a P-N junction. In a MOS-FET, the P-N junction
is replaced with metal-oxide, which turned out to be easier to mass produce in
microchips.)

Now imagine if the charge coming through the gate is positive. The positive base
attracts many electrons � suddenly the area around the base which used to be a
no-man’s-land opens up. The channel for current through the U becomes larger
than it was originally and much more electricity can flow through.

Alternating charge on the base, therefore, changes how much current goes through
the U. The incoming current can be used as a faucet to turn current on or off as
it moves through the rest of the transistor.

On the other hand, the transistor can be used in a more complex manner as well
— as an amplifier. Current traveling through the U gets larger or smaller in
perfect synch with the charge coming into the base, meaning it has the identical
pattern as that original weak signal. And, since the second current is connected
to a different voltage supply, it can be made to be larger. The current coming
through the U is a perfect replica of the original, only amplified. The
transistor is used this way for stereo amplification in speakers and
microphones, as well as to boost telephone signals as they travel around the
world.

 

Information and Theories

Post navigation

Previous Post: Are transistors Alien Technology?
Next Post: Point Contact Transistor

Related Posts

  • Real-Life Mad Scientists: Brukhonenko & Demikhov Information and Theories
  • How To Build Lucid Dream Goggles Information and Theories
  • Infamous American Serial Killers: Stano & Lucas Information and Theories
  • Why Do We Need Auras? Information and Theories
  • Pull electric current from the earth’s magnetic flux lines Information and Theories
  • A Guide to Hypnotism Information and Theories

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Recent Posts

  • The Meat Eater couple arrested for child abuse
  • The Meat-Eater boxer kidnapped and raped a young school Girl
  • Carnist man arrested for 198 years for raping and shooting a woman
  • Mitch McConnell- Eating Cow Corpses
  • Animal Flesh Eater Arrested: Felony Charges Serious Injury To 3 Month Old!

Recent Comments

No comments to show.

Archives

  • January 2021
  • December 2020
  • November 2020
  • October 2020
  • August 2020
  • July 2020
  • May 2020
  • June 2018
  • February 2018
  • July 2016
  • May 2016
  • February 2016
  • September 2015
  • July 2015
  • May 2015
  • April 2015
  • March 2015
  • January 2015
  • December 2014
  • November 2014
  • July 2014
  • March 2014
  • February 2014
  • January 2014
  • December 2013
  • November 2013
  • October 2013
  • September 2013
  • August 2013
  • July 2013
  • June 2013
  • May 2013
  • April 2013
  • March 2013
  • February 2013
  • January 2013
  • December 2012
  • November 2012
  • October 2012
  • September 2012
  • August 2012
  • July 2012
  • June 2012
  • May 2012
  • April 2012
  • March 2012
  • February 2012
  • January 2012
  • December 2011
  • November 2011
  • October 2011
  • September 2011
  • August 2011
  • July 2011
  • June 2011
  • May 2011
  • April 2011
  • March 2011
  • February 2011
  • January 2011
  • December 2010
  • November 2010
  • October 2010
  • September 2010
  • August 2010
  • July 2010
  • June 2010
  • May 2010
  • April 2010
  • March 2010
  • February 2010
  • January 2010
  • December 2009
  • November 2009
  • October 2009
  • September 2009
  • August 2009
  • July 2009
  • June 2009
  • May 2009
  • April 2009
  • March 2009
  • February 2009
  • January 2009
  • December 2008
  • November 2008
  • October 2008
  • September 2008
  • August 2008
  • July 2008
  • June 2008
  • May 2008
  • April 2008
  • March 2008
  • February 2008
  • January 2008
  • December 2007
  • November 2007
  • October 2007
  • September 2007
  • August 2007
  • July 2007
  • June 2007
  • May 2007
  • April 2007
  • March 2007
  • February 2007
  • January 2007
  • December 2006
  • November 2006
  • October 2006
  • September 2006
  • August 2006
  • July 2006
  • June 2006
  • May 2006
  • April 2006
  • March 2006
  • February 2006
  • January 2006
  • December 2005
  • November 2005
  • October 2005
  • September 2005
  • August 2005
  • July 2005
  • June 2005
  • May 2005
  • April 2005
  • March 2005
  • February 2005
  • January 2005
  • December 2004
  • November 2004
  • October 2004
  • September 2004
  • August 2004
  • July 2004
  • June 2004
  • May 2004
  • April 2004
  • March 2004
  • February 2004
  • January 2004
  • December 2003
  • November 2003
  • October 2003

Categories

  • Ancient Civilizations
  • Benjamin Fulford Story
  • Corrupt Carnivores
  • Cryptology and Monsters
  • Eating Healthy
  • Ghost And Demons
  • Information and Theories
  • Mars Coverage
  • Meditation And Spirituality
  • Mysteries
  • NASA Articles
  • Other Exciting News
  • Personal Accounts
  • Pictures And Multimedia
  • Political Conspiracies
  • Recent Submissions
  • Religion Articles
  • Self Improvement
  • Simply Unexplainable
  • Space and Astrology
  • Technology Articles
  • True Stories
  • UFOs and Aliens
  • Unexplainable Video Library
  • Unexplainable Weather
  • Scientific Astronomical Field Evaluation Information Information and Theories
  • Torch Wielding Cameraman Films Alien UFOs and Aliens
  • A Collection of Celestial Facts: Sun & Jupiter Space and Astrology
  • Ancient Sites of Rome: The Pantheon and Trajan’s Market Ancient Civilizations
  • KLAS Interview with Bob Lazar UFOs and Aliens
  • Beautiful Dreams and Horrible Nights Continued UFOs and Aliens
  • The Illinois UFO Alien Sightings of January, 2000, Part 1 UFOs and Aliens
  • Ancient Connections: Everyday Items Ancient Civilizations

Copyright © 2023 Unexplainable.net.

Powered by PressBook News Dark theme