Consumer Electronics

A2. Cleaning with toothpaste would be likely to leave the cleaner in the tiny grooves. And it is not common for small scratches to interfere with the playing of a CD or DVD. If you can detect the scratch in the reproduction, the time may be right for a visit to the shop.

A1 Yaaaaaa

The disadvantages of TTL are as follows:

1. High power consumption
2. It functions just on 5v
3. The fan-out capacity for this device is low
4. Low input resistance

IN US HISTORY, WHO INVENTED THE TELEPHONE?

Alexander Graham Bell, a Scottish-born inventor, scientist, philanthropist and teacher of the deaf is the person most widely credited as the inventor of the electric telephone. On March 7th 1876 he became the first to receive a patent for this device, and at that time resided in Salem, Massachusetts.

Alexander Graham Bell conceived of the telephone at his summer home in Brantford, Ontario and physically created his first phone in Boston, Massachusetts (where, he said, it was 'born'). This was a result of his research into improving the telegraph system. Bell was experimenting into improving the telegraph system so that multiple messages could be sent at the same time (his theory of the 'harmonic telegraph' was based on the principle that several messages could be sent simultaneously along the same wire if the different telegraph signals each had a different pitch). However at the same time he began working on the novel idea that speech could be transmitted electronically, as he accidentally discovered that the sound of a spring being twanged could be heard over his harmonic telegraph system. Almost a year later in March 1876 Bell uttered the first famous words into the device to his assistant in the next room: "Mr. Watson, come here -I want to see you".

A young black man, Lewis Lattimer, was employed as a draftsman by the patent law firm that Alexander Graham Bell used, and contributed to Bell's patent drawings. Lattimer become a successful inventor in his own right.

As with many other important technological devices, several people often worked on and independently created the same, or similar devices in the same general time period -an example being the modern navigational quadrant or sextant. While Bell was the first to receive a patent for the telephone, several others preceded his research and credit for inventing the electric telephone remains in dispute.

Despite the claims of those defending Alexander Graham Bell, its been suggested that both Antonio Meucci and then Elisha Gray successfully invented telephones in the United States before Alexander Graham Bell built his first one in 1876.

Earlier in 1831, Englishman Michael Faraday proved that vibrations of metal could be converted to electrical impulses. This was the technological basis of the telephone, but no one actually used this system to transmit sound until 1861. In that year, Johann Philip Reis in Germany is said to have built a simple apparatus that changed sound to electricity and back again to sound. It was a crude device and due to its design was incapable of transmitting many frequencies, consequently it was never fully developed.

Some of the others who performed pioneering experimental work with electrical voice transmissions over wires included Thomas Edison, Innocenzo Manzetti, and Charles Bourseul. Incredibly, both Bell's lawyer and Gray filed documents (Bell's lawyer a patent claim, and Gray a notice of a potential patent) on their designs on February 14, 1876, with Bell's application beating Gray's to the document examiner by only hours. Although Gray had built the first steel diaphragm-electromagnet receiver in 1874, he wasn't able to master the design of a workable transmitter until after Bell had. Bell had worked tirelessly, experimenting with various types of mechanisms, while Gray had become discouraged.

According to a famous story, the first fully intelligible telephone call occurred on March 6, 1876, when Bell, who had supposedly spilled acid on himself, called to his assistant in another room. "Mr. Watson, come here! I want to see you". Improvements followed rapidly. The first long distance telephone call was placed soon after between Brantford, Ontario, and Paris, Ontario. The first telephone exchange, a practical means of communicating between many people having telephones, was installed in Hartford, Connecticut in 1877, and the first exchange linking two major cities was established between New York and Boston in 1883. In 2002 the United States Congress passed resolution HRes 269 EH acknowledging the contributions of Antonio Meucci for his work in the telephone's development, stating: "That it is the sense of the House of Representatives that the life and achievements of Antonio Meucci should be recognized, and his work in the invention of the telephone should be acknowledged". Ironically this resolution has often being incorrectly misinterpreted as meaning that Meucci invented the telephone. However the congressional resolution did not state that he did, or state that Bell did not invent the telephone; it only served as a declaration on Meucci's contributions, and did not annul or modify any of the patents Bell received from 1876 onwards. The 2002 resolution was quickly followed by another legislative declaration in Canada upholding Bell's priority and his status as inventor of the telephone.

The person who first successfully 'patented' the telephone was indisputably Alexander Graham Bell, however earlier inventors of 'telephone-like devices' may have been Meucci or even others before him.

Interestingly, the commercialization of Alexander Graham Bell's telephone was actually performed by several independent businesses which eventually created the 'Bell System' (and later AT&T), to which 'Alec', as he preferred to be called, participated very little in. Alexander Graham Bell, who went on to become an eminent scientist, inventor and philanthropist, considered the telephone to be an intrusion into his real work and refused to have one in his study.

Further readings:

- for more information on Bell's personal life, his citizenship (although many Canadians claim him as an 'honorary' son since he lived in Canada for more than 37 years and died there as well, he was a U.S. citizen from 1882 onwards and wasnever actually Canadian), and his many other scientific and philanthropic accomplishments, see: Wikipedia.org: 'Alexander Graham Bell' and'Alexander Graham Bell honors and tributes'

- Charlotte Gray, "RELUCTANT GENIUS: THE PASSIONATE LIFE AND INVENTIVE MIND OF ALEXANDER GRAHAM BELL", HarperCollins/Phylilis Bruce, Toronto, 2006, ISBN: 0002006766, Dewey library code: 621.385092 Bell.

- for more information in the many other people who contributed to the electric telephone, see: Wikipedia.org:'History of the Telephone' and'Invention of the Telephone'

It is the department that looks after the electronic data processing needs of an organization. Today it would be better known as the IT of Information Technology dept. or Information Systems dept. Hope that is clear.

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EDP stands for Electronic Data Processing. There is a department that takes this name with an objective to control the inventory and stock, mainly, the movement of the goods between different locations, warehouse, and suppliers. This department undertakes the responsibility of managing continuous stocktaking and digital data integrity in the information system as well.

EDP department is independent from IT department, but uses the information systems and other services managed and supported by this department. Sometimes an IT qualified personnel works under the EDP department to speed up support process and coordinate with IT department.

Hope this information answers your question!

Show her why you need it! Are you gone a lot? Do you have a lot of friends to talk to? Otherwise, there's no reason for a cell phone. however, you need to show her you're responsible. Make a deal with her about you getting a cool cell phone with a neat minutes-plan if you do good on your next test...or something like that!

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I'm doing this project too and this is what I have so far. Can you believe she only gave us four days to do it. For me it will take a couple more days to complete.