Air Conditioners ; How they work

How Air Conditioners Work

­When the temperature outside begins to climb, many people seek the cool comfort of indoor ai­r conditioning. Like water towers and power lines, air conditioners are one of those things that we see every day but seldom pay much attention to.
Wouldn't it be nice to know how these indispensable machines work their magic?
Air conditioners come in various sizes, cooling capacities and prices. One type that we see all the time is the window air conditioner, an easy and economical way to cool a small area:

People who live in suburban areas usually have a condenser unit in the backyard:­

If you live in an apartment complex, you'll probably see multiple condensers for each dwelling:

Most businesses and office buildings have condensing units on their roofs, and as you fly into any airport you notice that warehouses and malls may have 10 or 20 condensing units hidden on their roofs:

At office complexes, you'll find large cooling towers that are connected to the air conditioning system:

Even though each of these machines has a pretty distinct look, they all work on the same principles. In this article, we'll examine air conditioners -- from small to huge -- so you know more about what you're seeing. We'll also look at some new, energy-efficient cooling methods.

Window and Split-system AC Units

A window air conditioner unit implements a complete air conditioner in a small space. The units are made small enough to fit into a standard window frame. You close the window down on the unit, plug it in and turn it on to get cool air. If you take the cover off of an unplugged window unit, you'll find that it contains:

• A compressor
• An expansion valve
• A hot coil (on the outside)
• A chilled coil (on the inside)
• Two fans
• A control unit

The fans blow air over the coils to improve their ability to dissipate heat (to the outside air) and cold (to the room being cooled).

When you get into larger air-conditioning applications, its time to start looking at split-system units. A split-system air conditioner splits the hot side from the cold side of the system, as in the diagram below.

The cold side, consisting of the expansion valve and the cold coil, is generally placed into a furnace or some other air handler. The air handler blows air through the coil and routes the air throughout the building using a series of ducts. The hot side, known as the condensing unit, lives outside the building.
The unit consists of a long, spiral coil shaped like a cylinder. Inside the coil is a fan, to blow air through the coil, along with a weather-resistant compressor and some control logic. This approach has evolved over the years because it's low-cost, and also because it normally results in reduced noise inside the house (at the expense of increased noise outside the house). Other than the fact that the hot and cold sides are split apart and the capacity is higher (making the coils and compressor larger), there's no difference between a split-system and a window air conditioner.
In warehouses, large business offices, malls, big department stores and other sizeable buildings, the condensing unit normally lives on the roof and can be quite massive. Alternatively, there may be many smaller units on the roof, each attached inside to a small air handler that cools a specific zone in the building.
In larger buildings and particularly in multi-story buildings, the split-system approach begins to run into problems. Either running the pipe between the condenser and the air handler exceeds distance limitations (runs that are too long start to cause lubrication difficulties in the compressor), or the amount of duct work and the length of ducts becomes unmanageable. At this point, it's time to think about a chilled-water system.

How an Air conditioner works.

Air-conditioning Basics

­ Most people think that air conditioners lower the temperature in their homes simply by pumping cool air in. What's really happening is the warm air from your house is being removed and cycled back in as cooler air. This cycle continues until your thermostat reaches the desired temperature.

An air conditioner is basically a refrigerator without the insulated box. It uses the evaporation of a refrigerant, like Freon, to provide cooling. The mechanics of the Freon evaporation cycle are the same in a refrigerator as in an air conditioner. According to the Merriam-Webster Dictionary Online, the term Freon is generically "used for any of various nonflammable fluorocarbons used as refrigerants and as propellants for aerosols."

Diagram of a typical air conditioner.

This is how the evaporation cycle in an air conditioner works (See How Refrigerators Work for complete details on this cycle):

1. The compressor compresses cool Freon gas, causing it to become hot, high-pressure Freon gas (red in the diagram above).
2. This hot gas runs through a set of coils so it can dissipate its heat, and it condenses into a liquid.
3. The Freon liquid runs through an expansion valve, and in the process it evaporates to become cold, low-pressure Freon gas (light blue in the diagram above).
4. This cold gas runs through a set of coils that allow the gas to absorb heat and cool down the air inside the building.

Mixed in with the Freon is a small amount of lightweight oil. This oil lubricates the compressor.
Air conditioners help clean your home's air as well. Most indoor units have filters that catch dust, pollen, mold spores and other allergens as well as smoke and everyday dirt found in the air. Most air conditioners also function as dehumidifiers. They take excess water from the air and use it to help cool the unit before getting rid of the water through a hose to the outside. Other units use the condensed moisture to improve efficiency by routing the cooled water back into the system to be reused.
So this is the general concept involved in air conditioning. In the next section, we'll take a look at window and split-system units.
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Inventors Hall of Fame: Nikola Tesla Nicola TeslaNikola Tesla Born Jul 10 1856 - Died Jan 7 1943 Electro-Magnetic Motor Alternating Current Patent Number 381,968 (.PDF) Inducted to National Inventors Hall of Fame™ in 1975 Nikola Tesla invented the induction motor with rotating magnetic field that made unit drives for machines feasible and made AC power transmission an economic necessity. In 1887 and 1888 Tesla had an experimental shop at 89 Liberty Street, New York, and there he invented the induction motor. He sold the invention to Westinghouse in July 1888 and spent a year in Pittsburgh instructing Westinghouse engineers. Invention Impact Alternating current (AC) became the premier form of electrical energy after it overcame objections by Thomas Edison who designed direct current (DC). Tesla also showcased his invention at the 1893 Chicago World’s Fair where he and Westinghouse won the bid to illuminate the International Exhibition. Alternating current captivated the public with its efficient lighting and lessened heat. Nikola Tesla developed polyphase alternating current system of generators, motors and transformers and held 40 basic U.S. patents on the system, which George Westinghouse bought, determined to supply America with the Tesla system. Tesla Memorial Society of New York Website AC has an electric current whose direction reverses cyclically rather than staying in a constant direction like DC. The waveform of AC is also more efficient than the DC. AC is the form in which electricity is carried to homes and businesses. Radiant Energy Patent When thinking about the 1900 turn-of-the-century you don't think of high-tech but Nikola Tesla certainly was one of the geniuses of the century. One of the most interesting patents I found was US patent number 685,958 (.PDF) for a Method of Using Radiant Energy. If you look closely at the original patent drawing below you can see someone hand wrote: "electric stepping motor energized by corpuscular energy from the sun." Was this the precursor of the Solar Panel? This reminds me of how in 1880 Alexander Graham Bell invented the photophone-transmission of sound on a beam of light- a precursor of today's optical fiber systems. Method of Using Radiant Energy energy from sunInventor Bio Born in Smiljan Lika, Croatia, the son of a Serbian Orthodox clergyman, Tesla attended Joanneum, a polytechnic school in Graz and the University of Prague for two years. He started work in the engineering department of the Austrian telegraph system then became an electrical engineer at an electric power company in Budapest and later at another in Strasbourg. While in technical school, Tesla became convinced that commutators were unnecessary on motors; and while with the power company he built a crude motor which demonstrated the truth of his theory. In 1884, Tesla came to the United States and joined the Edison Machine Works as a dynamo designer. Telsa obtained more than 100 patents in his lifetime. Despite his 700 inventions Tesla was not wealthy. For many years he worked in his room at the Hotel New Yorker, where he died. Posted with the permission of the National Inventors Hall of Fame™ Tags: Interesting Stuff, Inventors, National Inventors Hall of Fame, Nikola Tesla, Patents, inventor * Email This * Print * Comments * Trackbacks * Share Link Posted on December 27, 2010 by Vincent LoTempio Inventors Hall of Fame: Alexander Graham Bell Alexander Graham Bell Born Mar 3 1847 - Died Aug 2 1922 Telephone / Telegraphy Patent Number 174,465 Inducted to National Inventors Hall of Fame™ in 1973 Alexander Graham Bell's invention of the telephone grew out of his research into ways to improve the telegraph. On April 6, 1875, Bell was granted the patent for the multiple telegraph, which sent two signals at the same time. In September 1875 he began to write the specifications for the telephone. On March 7, 1876, the U.S. Patent Office granted him Patent Number 174,465 (PDF) covering, the method of, and apparatus for, transmitting vocal or other sounds telegraphically by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sounds. Inventor Bio Born in Edinburgh, Scotland, the inventor spent one year at a private school, two years at Edinburgh's Royal High School (from which he graduated at 14), and attended a few lectures at Edinburgh University and at University College in London, but he was largely family-trained and self-taught. He also worked in medical research and invented techniques for teaching speech to the deaf. In 1888 he founded the National Geographic Society. Never adept with his hands, Bell had the good fortune to discover and inspire Thomas Watson, a young repair mechanic and model maker, who assisted him enthusiastically in devising an apparatus for transmitting sound by electricity. After inventing the telephone, Bell continued his experiments in communication, which culminated in the invention of the photophone-transmission of sound on a beam of light- a precursor of today's optical fiber systems. Photophone Invention Impact The range of Bell's inventive genius is represented only in part by the 18 patents granted in his name alone and the 12 he shared with his collaborators. These included: * 14 for the telephone and telegraph, * 4 for the photophone (PDF), * 1 for the phonograph (PDF), * 5 for aerial vehicles (PDF), * 4 for hydroairplanes (PDF), and * 2 for a selenium cell (PDF). Posted with the permission of the National Inventors Hall of Fame™ Tags: Alexander Graham Bell, Inventors, National Inventors Hall of Fame, Patents * Email This * Print * Comments * Trackbacks * Share Link Posted on November 22, 2010 by Vincent LoTempio Inventors Hall of Fame: Thomas Alva Edison Thomas Alva EdisonThomas Alva Edison Born Feb 11 1847 - Died Oct 18 1931 Electric Lamp Patent Number: 223,898 (.PDF) Inducted to National Inventors Hall of Fame™ in 1973 Invention Impact Throughout his career, Edison consciously directed his studies to devices that could satisfy real needs and come into popular use. Indeed, it may be said that in applying himself to technology, he was fulfilling the ideals of democracy, for he centered his attention upon projects that would increase the convenience and pleasure of mankind. One of the outstanding geniuses in the history of technology, Thomas Edison created the world's first industrial research laboratory. Edison earned patents for more than a thousand inventions, including: * Incandescent Electric Lamp (PDF), * Phonograph (PDF), * Carbon Telephone Transmitter (PDF), and * Electrical System for Automobiles (PDF). In September 1878, after having viewed an exhibition of a series of eight glaring 500-candlepower arc lights, Edison boldly announced he would invent a safe, mild, and inexpensive electric light that would replace the gaslight in millions of homes; moreover, he would accomplish this by an entirely different method of current distribution from that used for arc lights. To back the lamp effort, some of New York's leading financial figures joined with Edison in October 1878 to form the Edison Electric Light Company, the predecessor of today's General Electric Company. On October 21,1879, Edison demonstrated the carbon-filament lamp, supplied with current by his special high-voltage dynamos. The pilot light-and-power station at Menlo Park glowed with a circuit of 30 lamps, each of which could be turned on or off without affecting the rest. Three years later, the Pearl Street central power station in downtown New York City was completed, initiating the electrical illumination of the cities of the world. In 1887 Edison moved his workshop from Menlo Park to West Orange, New Jersey, where he built the Edison Laboratory (now a national monument), a facility 10 times larger than the earlier one. In time it was surrounded with factories employing some 5,000 persons and producing a variety of new products, among them his improved phonograph using wax records, the mimeograph, fluoroscope, alkaline storage battery, dictating machine, and motion-picture cameras and projectors. During World War I, the aged inventor headed the Naval Consulting Board and directed research in torpedo mechanisms and antisubmarine devices. It was largely owing to his urging that Congress established the Naval Research Laboratory, the first institution for military research, in 1920. Inventor Bio Born in Milan, Ohio, Edison was an inquisitive child. By the time he was 10 he had set up a small chemical laboratory in the cellar of his home after his mother had aroused his interest in an elementary physical science book. He found the study of chemistry and the production of electrical current from voltaic jars especially absorbing and soon operated a homemade telegraph set. In 1868 he obtained a position in Boston as an expert night operator for Western Union Telegraph Company; by day he slept little, however, for he was gripped by a passion for manipulating electrical currents in new ways. Borrowing a small sum from an acquaintance, he gave up his job in the autumn of 1868 and became a free-lance inventor, taking out his first patent for an electrical vote recorder. In the summer of 1869 he was in New York, sleeping in a basement below Wall Street. At a moment of crisis on the Gold Exchange caused by the breakdown of the office's new telegraphic gold-price indicator, Edison was called in to try to repair the instrument; this he did so expertly that he was given a job as its supervisor. Soon he had remodeled the erratic machine so well that its owners, the Western Union Telegraph Company, commissioned him to improve the crude stock ticker just coming into use. The result was the Edison Universal Stock Printer, which, together with several other derivatives of the Morse telegraph, brought him a sudden fortune of $40,000. With this capital he set himself up as a manufacturer in Newark, New Jersey, producing stock tickers and high-speed printing telegraphs. In 1876 Edison gave up the Newark factory altogether and moved to the village of Menlo Park, New Jersey, to set up a laboratory where he could devote his full attention to invention. He promised that he would turn out a minor invention every ten days and a big invention every six months. He also proposed to make inventions to order. Before long he had 40 different projects going at the same time and was applying for as many as 400 patents a year.

50 Inventiomns that affected mankind.

Since time immemorial, thousands of inventions by man have gone on to transform the world. Here is a list of 50 (in alphabetical order) that may have played a bigger part than most:

Abacus- 190 AD


Use of the abacus, with its beads in a rack, was first documented in China in about 190 AD. The Chinese version was the speediest way to do sums for centuries and, in the right hands, can still outpace electronic calculators.


Aspirin- 1899


Little tablets of acetylsalicylic acid have probably cured more minor ills than any other medicine. Hippocrates was the first to realise the healing power of the substance. At the turn-of-the-century, German chemist Felix Hoffman perfected the remedy.


Barbed wire- 1873


The world's most divisive invention was conceived not to keep people in or out, but cows.

Barcode- 1973


Barcodes were conceived as a kind of visual Morse code by a Philadelphia student in 1952. Now, black stripes have appeared on almost everything we buy.


Battery- 1800


In 1780s, Italian physicist Luigi Galvani discovered that a dead frog's leg would twitch when he touched it with two pieces of metal. His friend, professor Alessandro Volta made the first battery which were voltaic cells stacked in a Voltaic pile.

Frank Henry Fleer...Invented the bubble gum, and it's history: below.

 

The History of Chewing Gum and Bubble Gum

• The ancient Greeks chewed mastiche - a chewing gum made from the resin of the mastic tree.
• The ancient Mayans chewed chicle which is the sap from the sapodilla tree.
• North American Indians chewed the sap from spruce trees and passed the habit along to the settlers.
• Early American settlers made a chewing gum from spruce sap and beeswax.
• In 1848, John B. Curtis made and sold the first commercial chewing gum called the State of Maine Pure Spruce Gum.
• In 1850, Curtis started selling flavored paraffin gums becoming more popular than spruce gums.
• On December 28 1869, William Finley Semple became the first person to patent a chewing gum - U.S patent #98,304.
• In 1869, Antonio Lopez de Santa Anna introduced Thomas Adams to chicle.
• In 1871, Thomas Adams patented a machine for the manufacture of gum.
• In 1880, John Colgan invented a way to make chewing gum taste better for a longer period of time while being chewed.
• By 1888, an Adams' chewing gum called Tutti-Frutti became the first chew to be sold in a vending machine. The machines were located in a New York City subway station.
• In 1899, Dentyne gum was created by New York druggist Franklin V. Canning.
• In 1906, Frank Fleer invented the first bubble gum called Blibber-Blubber gum. However, the bubble blowing chew was never sold.
• In 1914, Wrigley Doublemint brand was created. William Wrigley, Jr. and Henry Fleer were responsible for adding the popular mint and fruit extracts to a chicle chewing gum.
• In 1928, an employee of the Frank H. Fleer Company, Walter Diemer invented the successful pink colored Double Bubble, bubble gum. The very first bubble gum was invented by Frank Henry Fleer in 1906. He called it Blibber-Blubber. Fleer's recipe was later perfected by Walter Diemer, who called his product Double Bubble.

ANNE MOORE..Invented the Snugli Babt carrier

Ann Moore

The Snugli® Baby Carrier

As a Peace Corps nurse during the 1960s in Togo, West Africa, Ann Moore saw African mothers do something that she found very interesting: they carried their babies in fabric slings tied securely on their backs. Moore liked the closeness between babies and their mothers when carried in this way. She observed how the babies seemed so calm because they felt secure and near to their mothers.

When Moore came back home to the United States and decided to have her own child, she wanted to carry her baby in the same manner. After her daughter Mandela was born, Moore attempted to secure the baby on her back just as she had seen in Africa, but the child kept slipping. Starting from a simple backpack and then refining it to their needs, Moore and her mother designed a carrier similar to the ones used by the women in Togo. Together, they came up with the original soft baby carrier, the Snugli®, as well as other kinds of specialized carrying cases.
Due to their invention, mothers and fathers all over the world are able to ride bikes, cook and run errands while carrying their babies close to them. Here is a picture of Moore with the Snugli®.

MARGARET KNIGHT..Inventor of the Paper bag and other items.

Margaret Knight

Invention of the Paper Bag Machine

For many women inventors in years past, the invention process was twice as difficult because, in addition to the hardships of inventing, they also faced the skepticism of a world that didn't believe women could create something of value. Fortunately, over the years, that perception has been blown out of the water by women inventors like Margaret E. Knight, who were willing to fight for the accolades and recognition they unquestionably deserved.
Born in Maine in 1838 and raised by a widowed mother, Margaret Knight showed a proclivity toward inventing from a very young age – a characteristic of many of the world's famous inventors. After observing an accident at a textile mill at the age of 12, Margaret went to work producing her first real invention. Knight conceived a device that would automatically stop a machine if something got caught in it. By the time she was a teenager the invention was being used in the mills.

After the Civil war, Margaret Knight went to work in a Massachusetts paper bag plant. While working in the plant, Knight thought how much easier it would be to pack items in paper bags if the bottoms were flat (they were not at the time). That idea inspired Margaret to create the machine that would transform her into a famous woman inventor. Knight's machine automatically folded and glued paper-bag bottoms – creating the flat-bottom paper bags that are still used to this very day in most grocery stores.

Of course, no story of triumph would be complete without a villain. In this case, the villain was a man named Charles Annan – who attempted to steal Knight's idea (he spied on the woman hired to make her prototype) and receive credit for the patent. Not one to give in without a fight, Margaret took Annan to court to vie for the patent that rightfully belonged to her. While Annan argued simply that a woman could never design such an innovative machine, Knight displayed actual evidence that the invention indeed belonged to her. As a result, Margaret Knight received her patent in 1871.
Knight's invention immediately had a huge impact on the paper industry – and paper bags began to proliferate throughout the retail landscape. To this very day, thousands of machines based on Margaret Knight's idea are still used to produce flat-bottom paper bags. Knight didn't stop there though; throughout her lifetime she would receive over 20 patents and conceive almost 100 different inventions – including a rotary engine, shoe-cutting machine and a dress and skirt shield. At the time of her death, an obituary described Knight as a "woman Edison." In actuality, she was something greater – she was a woman inventor named Margaret Knight.

Charles Goodyear and John Dunlop..All about tires

History of Tires
Charles Goodyear invented vulcanized rubber in 1844 that was later used for the first tires.
By Mary Bellis Charles Goodyear invented vulcanized rubber in 1844 that was later used for tires. In 1888, John Dunlop invented the air-filled or pneumatic tires, however, his were for bicycles.  In 1895, André Michelin was the first person to use pneumatic tires on an automobile, however, not successfully.  In 1911, Philip Strauss invented the first successful tire, which was a combination tire and air filled inner tube. Strauss' company the Hardman Tire & Rubber Company marketed the tires.  In 1903, P.W. Litchfield of the Goodyear Tire Company patented the first tubeless tire, however, it was never commercially exploited until the 1954 Packard.  In 1904, mountable rims were introduced that allowed drivers to fix their own flats. In 1908, Frank Seiberling invented grooved tires with improved road traction.  In 1910, B.F. Goodrich Company invented longer life tires by adding carbon to the rubber.  Goodrich also invented the first synthetic rubber tires in 1937 made of a patented substance called Chemigum. Pneumatic Tyre (Tire) John Boyd Dunlop (1840-1921) was a Scottish veterinarian and the recognized inventor of the first practical pneumatic or inflatable tyre/tire. His patent was for a bicycle tire, granted in 1888. However, Robert William Thomson (1822 - 1873) invented the actual first vulcanised rubber pneumatic tire. Thomson patented his pneumatic tire in 1845, his invention worked well but was to costly to catch on. Dunlop's tire patented in 1888 did, and so he received the most recognition. William Thomson also patented a fountain pen (1849) and a steam traction engine (1867).

COBOL; computer language inventor..GRACE HOPPER

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COBOL

The achievements of Admiral Grace Murray Hopper which, most notably, include the invention of the compiler, cemented her place at the forefront of the computing revolution that began in the early 1940s. Trained as a mathematician, her career spanned six decades during which she remained simultaneously connected across several disciplines and industries, including academia, industry and the U.S. military. Born Grace Brewster Murray on December 9, 1906 in New York City, she was the eldest of three children, and shared with her mother an affinity for mathematics. She attended Vassar College, from where she graduated in 1928, Phi Beta Kappa, with a BA in mathematics and physics. She took on a teaching post there while she pursued graduate studies at Yale University, completing MA and PhD degrees in mathematics at Yale in 1930 and 1934, respectively.
Meanwhile, in 1930, she married Vincent Foster Hopper, an English instructor with the New York School of Commerce, whom she divorced several years later. She continued to teach at Vassar, achieving the rank of associate professor in 1941, when she was awarded a fellowship at New York University's Courant Institute for Mathematics.
Hopper made a life-altering decision in 1943 when she decided to join the World War II effort and enlist with Navy WAVES, for Women Accepted for Voluntary Emergency Service, in December of that year. Her family had strong military ties, thus this was not a totally unexpected move for Hopper; however, it presented her with extraordinary opportunities to contribute to the early development of computing machines. In July 1944, having been commissioned a lieutenant, she became part of the team working on the Bureau of Ordnance Computation Project at Harvard University, along with professor and Naval Reserve officer Howard H. Aiken. Aiken was the principal engineer behind IBM's Harvard Mark I computer, considered the first large-scale automatic digital computer in the United States.
As the third person to have the opportunity to work on this machine, Hopper dove in and learned to program it, in the process authoring a 500-page manual of operations that would serve to lay down lasting principles for computer operation. She went on to work with the Mark II and III machines and was later recognized for her achievements with a Naval Ordnance Development Award. In 1946 she returned to inactive duty and joined the Harvard faculty as a research fellow, where she continued her computing research until 1949.
That year she accepted a post as senior mathematician with Eckert-Mauchly Computer, which was purchased in 1950 by Remington Rand and merged into the Sperry Corporation in 1955. During this period, Hopper developed the revolutionary concept of the compiler, an intermediate program that translates instructions written in English into code that may be understood by the computer. Normally, programmers would have to write programs out in binary code, consisting of long series of zeros and ones. A compiler would allow a programmer to compose code more quickly and easily, without as much room for error, using English commands.
Hopper's first compiler, A-O, was unveiled in 1949, and used symbolic mathematical code to represent binary code combinations. This she followed up with B-O, or "Flow-Matic," considered the first English language data-processing compiler. This was used to program UNIVAC I and II machines by the end of 1956. The UNIVAC, which stands for Universal Automatic Computer, was among the first commercially available computers in the Unites States, built by Sperry Rand.
When discussions arose as to how to create a standardized, universal computer language, Hopper was deeply involved in the development of COBOL; her Flow-Matic compiler was used to help form a basis for the language, and she designed standard manuals and tools for it as well as translator programs that converted non-standard COBOL languages into the standard version. The first specifications for COBOL were made available in 1959.
Hopper retired from the Naval Reserves in 1966; however, in 1967 she took military leave from Sperry when she was called back into active duty to help the Navy standardize high-level computing languages. Her service was extended indefinitely, and she officially retired from Sperry in 1971.
For the Navy, Hopper worked on high-level computing research and development, including formula translation, code optimization and subroutines. She also educated thousands of people on the use of compilers and computer language standardization via speaking engagements throughout the world. In 1983 she was promoted to commodore at a ceremony that took place at the White House in Washington, D.C. She became Admiral Hopper in 1985 when this post was merged with rear admiral. She retired from the Navy in 1986.
Hopper then became a senior consultant to Digital Equipment Corporation, where she worked well into her 80s. She was awarded a National Medal of Technology in 1991, and was honored with more than 40 honorary doctoral degrees, as well as the first ever Computer Science Man-of-the-Year Award from the Data Processing Management Association in 1969. A U.S. warship was also named in her honor. In 1973, she became the first person from the United States, and the first woman from any nation, to become a Distinguished Fellow of the British Computer Society.
Hopper died on January 1, 1992, and was buried with full military honors in Arlington National Cemetery.

Karl Benz ; the Inventor of the four stroke car engine.

Karl Benz (Carl Benz)

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Karl Benz (Carl Benz)
In 1885, German mechanical engineer, Karl Benz designed and built the world's first practical automobile to be powered by an internal-combustion engine. On January 29, 1886, Benz received the first patent (DRP No. 37435) for a gas-fueled car. It was a three-wheeler; Benz built his first four-wheeled car in 1891. Benz & Company, the company started by the inventor, became the world's largest manufacturer of automobiles by 1900.
Biography
Karl Friedrich Benz was born in 1844 in Baden Muehlburg, Germany (now part of Karlsruhe). He was the son of an engine driver. Benz attended the Karlsruhe grammar school and later the Karlsruhe Polytechnic University. In 1871, He founded his first company with partner August Ritter, the "Iron Foundry and Machine Shop" a supplier of building materials.
Benz began his work on a two-stroke engine, in hopes of finding a new income. He received his first patent in 1879. In 1883, he founded Benz & Company to produce industrial engines in Mannheim, Germany. He then began designing a "motor carriage", with a four-stroke engine (based on Nicolaus Otto's patent). Benz designed his engine (958cc, 0.75hp) and the body for the three-wheel vehicle with an electric ignition, differential gears, and water-cooling. The car was first driven in Mannheim in 1885. On January 29, 1886, he was granted a patent for his gas-fueled automobile (DRP 37435) and in July, he began selling his automobile to the public.

The Inventions of Thomas Edison
History of Phonograph - Lightbulb - Motion Pictures
Replica of original phonograph
Phonograph - History The first great invention developed by Edison in Menlo Park was the tin foil phonograph. While working to improve the efficiency of a telegraph transmitter, he noted that the tape of the machine gave off a noise resembling spoken words when played at a high speed. This caused him to wonder if he could record a telephone message. He began experimenting with the diaphragm of a telephone receiver by attaching a needle to it. He reasoned that the needle could prick paper tape to record a message. His experiments led him to try a stylus on a tinfoil cylinder, which, to his great surprise, played back the short message he recorded, "Mary had a little lamb." The word phonograph was the trade name for Edison's device, which played cylinders rather than discs. The machine had two needles: one for recording and one for playback. When you spoke into the mouthpiece, the sound vibrations of your voice would be indented onto the cylinder by the recording needle. This cylinder phonograph was the first machine that could record and reproduce sound created a sensation and brought Edison international fame.