Electronic Television

The first man to envision an electronic television system was a British electrical engineer named A. Cambell Swinton. In a speech he gave in 1911, Swinton described a design using cathode-ray tubes to both capture the light and display an image. A cathode-ray tube was a glass bottle with a long neck on one end and a flattened screen on the other. The bottle was pumped clear of air so that an "electron gun" in the neck could shoot a stream of electrons toward the flattened end of the tube which was covered with a coating of phosphor material. When the electrons hit the material it would glow. By sweeping the electron stream back and forth in rows from top to bottom and varying the intensity of the stream, Swinton reasoned, an image could be drawn in the same manner that Nipkow's disks did.

A modified version of the tube could also be used as a camera. If the flattened end could be given a sandwich of metal, a non-conducting material and a photoelectric material, light focused on the flattened end with a lens would produce a positive charge on the inside of the surface. By sweeping the electron stream across the flattened end, again in rows, the charges could be read and the image could be turned into a signal that could be sent to the display screen to be seen.

Swinton's idea almost exactly describes the way modern electronic television works. While his forevision was near perfect, Swinton, nor anyone else at the time, knew how to actually engineer such a system and make it work. An electronic system, if it could be made to work, however, would operate at much faster speeds than any mechanical system could and would allow the picture to be composed of more rows, therefore increasing the quality of the image.

It was eleven years after Swinton's lecture that a teenager from Utah became interested in electronic television. Philo T. Farnsworth had read about Nipkow's disc system and decided it would never produce a high quality picture. After experimenting with electricity, he declared to one of his high school teachers that he thought he could devise a better system. He proceeded to lay it out for the surprised man on the classroom blackboard. The teacher encouraged Farnsworth and Farnsworth set out to California to build a laboratory where he could experiment with his ideas. Working in darkened rooms in Los Angeles and later San Francisco, Farnsworth kept his work so secret that his laboratory was once the subject of a raid by police, who thought that he was using a still to produce illegal alcoholic beverages.

By September of 1927 Farnsworth was transmitting a sixty line picture from camera to screen using an entirely electronic system. It was at this point in time his work drew the attention of David Sarnoff. Sarnoff was chief of the Radio Corporation of America (RCA): the leader in supplying radios and radio parts to the United States.

Many of RCA's radio patents would soon expire, so Sarnoff was searching for another market he could corner and television was the obvious choice. After hiring Vladimir Zworykin, a Russian immigrant who had been experimenting with mechanical television for a decade, Sarnoff sent him to California to look at Farnsworth's work. Later Sarnoff would visit Farnsworth's laboratory himself.

Sarnoff and Zworykin quickly realized the value of Farnsworth's invention and Sarnoff tried to buy the young man out for $100,000. Farnsworth, thinking he could make more in collecting patent royalties from RCA than selling his invention to them, refused. Sarnoff, miffed, said, "Then there's nothing here we'll need" and sent Zworykin off to build their own version of the technology.

Farnsworth's designs kept showing up in Zworykin's work and lawsuits between the two companies followed. Eventually RCA was forced to pay Farnsworth $1,000,000 in licensing fees, but the onset of WW II delayed the introduction of television to most of the United States and the market for electronic television did not really take off until after the war. By then many of Farnsworth's key patents had expired and he never made the money he probably really deserved for his contributions to electronic television.

SIR JAGADISH CHANDRA BOSE the unsung hero of radio communication

Sir J.C. Bose did his original scientific work in the area of Microwaves. He made his own equipment by employing an illiterate tin-smith whom he trained up to do the job for him. He produced extremely short waves and done considerable improvement upon Hertz's detector of electric waves. He produced a compact appratus for generating electromagnetic waves of wavelengths 25 to 5 mm and studying their quasioptical properties, such as refraction, polarization and double refraction. These could be demonstrated by his compact apparatus mounted on an ordinary spectrometer table. The most satisfactory polarizers and analyzers were made out of pressed jute fibres or books with laminated pages. He could even produce rotation of plane of polarization by transmission of electric rays through bundle of twisted jute fibres. The originality and simplicity of his apparatus were its remarkable features. Bose's research on response in living and non-living led to some significant findings: in some animal tissues like muscles, stimulation produces change in form as well as electrical excitation, while in other tissues (nerves or retina), stimulation by light produces electric changes only but no change of form. He showed that not only animal but vegetable tissues under different kinds of stimuli-mechanical, application of heat, electric shock, chemicals, drugs- produce similar electric responses.

the microwave transmitter developed by bose

The Wright brothers

Wilbur and Orville Wright invented the airplane in 1903. When they invented the first motor driven aircraft, the glider had already been in use.

Their first flight was in Kitty Hawk, North Carolina. When they were there they built gliders and experimented with them again and again. They also learned how the glider works and in two years they were geniuses on the glider.

Every time the Wright Brothers made a flight, they tried to figure out why it worked. For example, they studied the air conditions.

After they had been studying the glider for a while, they decided to add a gasoline engine. The gasoline engines then were big and heavy, so their goal was to build a lighter and smaller one.

The Wright Brothers had a bicycle shop in Dayton, Ohio, where they grew up, and whenever they needed to build something, they returned to the shop and built it there. So they went to the shop and started working on the engine.

When they finally built the engine, they went back to Kitty Hawk and tried it out. On December 17, 1903, they chose a few people to watch them fly the plane. The watchers were both so excited, for the Wright Brothers had flown for fifty-nine seconds.

They continued to work on new airplane designs and made a record on November 9, 1904, when Wilbur circled the prairie 4 times in 5 minutes. They used their Flyer. It weighed 700 pounds.

When they flew their 1905 Flyer, it lasted in the air for 39 minutes. After that flight, they decided that they should rest for a while, so for the next two years they did not fly or let anyone see their 1905 Flyer which used a motor and two propellers. The propellers turned different ways.

I hope you learned a lot about The Wright Brothers!

Steve Jobs and Steve Wozniak

Two Great Minds
Working Together

Two great minds, one interest. Two important men, one invention. Two close friends, one story. The story of Steve Jobs and Steve Wozniak.

Steven was born On February 4, 1955. He was then adopted by Paul and Clara Jobs. His father had many "jobs," (Ha ha! Get it? Jobs, has many jobs!), so his family moved a lot. As a young man, Steven put his interests to work in many ways, including working for Hewlett-Packard.

He learned a lot from his neighbor. His neighbor made a microphone. Steve was so interested he cornered this neighbor and asked him questions until he understood. His neighbor was so fascinated with such a young mind being interested in electronics, he taught Steven all he knew.

Stephen Wozniak, or "Woz", was five years older than Steve. He loved to make crazy gadgets. He showed Steve many of his gadgets.

When Steve and Woz were a little older, and more advanced in electronics, they would play practical jokes. Here's their most famous one. There was something called a "blue box." Crooks used to get free phone calls by breaking into the phone company's system. After long hard hours, Steve and Woz had invented their own blue box, which they sold to many people.

They weren't famous for inventing the blue box, but they invented a computer called the ready-made PC. PC stands for personal computer. They called their first computer the Apple I.

There were two main reasons it was invented. It was invented to "wow" or shock Steve and Woz's friends. The other reason was just plain fun. It was invented for computer games, especially an arcade game called "Breakout." In the game you used a paddle and ball to knock out bricks. This computer was made with speakers and a color code.

Their system made it cheaper and easier for people, other than computer specialists, to have a computer. Their company, Apple Computer, became successful and they created a new computer called the Apple II. Soon businesses, families, and schools were using the Apple II.

Apple was extremely successful in sales, until IBM made things very difficult for them. IBM made their own PC. Apple sales dropped tremendously. Apple needed a new plan. That's when Apple made the Macintosh computer. That brought another big success!

To Steven and Stephen, we say,

"Great Job!"

Benjamin Franklin(1706-1790)

Ben Franklin was most famous for the invention of the Franklin stove and also famous for his discoveries about lightning and electricity.

Ben conducted an experiment with electricity and proved that lightning is electricity. The experiment used a key, a kite, a wire, and jar full of water. The electricity hit the kite and it traveled to the key that was touching the wire which was in the jars.

Ben experimented with the electricity and sent a letter to a friend in London telling him about the night with the jars. The letter didn't get there and was picked up by a man and the word spread that Ben had found out how to catch electricity. Countries all over the world were using Ben's experiment.

Ben was very cold one morning and asked his wife, "Why is it so cold in here? Isn't our fireplace on?" She answered, "Yes it is on but it's just not powerful enough to make the whole room warm." Ben had an idea to make the whole house warm. It would be called the Franklin stove. It gave more heat and used less fuel than any other stove. As he built it with helpers and workers, one of them said, "You know Ben you can make a lot of money off of this invention." In return Ben said that he did not want the money. He just wanted to help citizens. Later a man changed the stove and improved it, making him very rich.

Benjamin Franklin(1706-1790)

Ben Franklin was most famous for the invention of the Franklin stove and also famous for his discoveries about lightning and electricity.

Ben conducted an experiment with electricity and proved that lightning is electricity. The experiment used a key, a kite, a wire, and jar full of water. The electricity hit the kite and it traveled to the key that was touching the wire which was in the jars.

Ben experimented with the electricity and sent a letter to a friend in London telling him about the night with the jars. The letter didn't get there and was picked up by a man and the word spread that Ben had found out how to catch electricity. Countries all over the world were using Ben's experiment.

Ben was very cold one morning and asked his wife, "Why is it so cold in here? Isn't our fireplace on?" She answered, "Yes it is on but it's just not powerful enough to make the whole room warm." Ben had an idea to make the whole house warm. It would be called the Franklin stove. It gave more heat and used less fuel than any other stove. As he built it with helpers and workers, one of them said, "You know Ben you can make a lot of money off of this invention." In return Ben said that he did not want the money. He just wanted to help citizens. Later a man changed the stove and improved it, making him very rich.

Henry Ford(July 30, 1863 - April 7, 1947)

Have you ever heard of a car called the Ford? I bet you know someone who has one like the Explorer, Windstar, Expedition, Contour, Mustang, or Tempo. Those are some of the cars that Henry Ford's company created. Have you ever wanted to know how it all started or who invented it or some other interesting facts?

Henry Ford was born in Dearborn, Michigan on July 30, 1863. His mom died at an early age. His dad's name was William Ford. Henry Ford had been raised on a farm and disliked farm life!

When Henry was 15 he went to Detroit and trained as a machinist. After that in 1888 he married Clara Bryant. They had one son named Edsel who was born November 6, 1893. Henry began to experiment with carriages without horses. In 1890 he invented the "Quadricycle." He wanted to invent affordable cars so that not only rich people could buy them, but also average people could. He tried to build cars so they would not cost too much. He was able to do it by inventing the assembly line. The assembly line helped Henry produce more cars faster which made them cheaper.

In 1903 Ford helped establish the Ford Motor Company, and from 1906-1919 he served as president as well as in 1943-1945. His whole family worked for the company and the development of the automotive industry. Henry named his cars with letters from the alphabet. They were called the Model A or Model T, but the Model T was the most famous. It was often called "Tin Lizzie" or the "Flivver." The Model T was developed in 1908. It was a four cylinder 20-hourspower car. The demand was high, but the supply was low. The car was really popular! The higher the demand got the more they made, and the price for the car decreased. In 1908 the Model T cost about $850 and by 1925 it was only $290. The Model T finally succumbed to a shift in public taste for more sophisticated and attractively styled cars. Production creased on May 31, 1927 when # 15,007,003, the last Model T was ever built. In September of 1917

Henry Ford II was born. He became president of the company right after his dad in 1945. Unlike his father, Henry the II went to college at Yale University. Henry the II retired between 1979-1980.

Until this day the Ford company still manufactures cars in Detroit. It expanded to own Jaguar and Volvo. Members of the Ford family still work in the automotive industry.