In the last quarter of the XIX century, Morse Telegraph became a fully organised public service with its standard tools, rules and specialists. and countless researchers were working harder to improve. His efforts were especially followed by two aspects: providing the maximum speed to cover costs as soon as possible; And to leave the Morse alphabet aside and receive messages in normal writing...
They provided the first through duplex (bilateral communication) technique, i.e. sending messages in both directions. This beautiful invention was the work of two people: Wheatstone (1852) and American Stearns (1868). The famous Thomas Edison also put this into a quadruplex system in 1871.
The first solution for the second problem was the British David Hughes (1831-1900). 1855 ′ proposed a keyboard corresponding to the letters of the alphabet. But still the most rooted solution was a simple telegraph technician who showed the French Emile Baudot (1845-1903). In 1874, a mixed road was offered to combine the Morse machines used by Hughes and his company. And he managed to accomplish that. Thus, it did not make a written telegram, but also the possibility of sending a few messages (5-6 Taneyini).
Baudot, a heady man, succeeded in taking his invention and accepting his machine to P.T.T.. Although it is not said that it gives him a lot of satisfaction, he has khurto see that his name remains a genus name to future generations, such as Morse.
The phone was invented during the first try of Baudot.
This invention has had a long history. Let's leave the first, my record: The phone (Hooke) aside; In 1782, after the voice of Pastor Dom Gauthey, who tried to take away the voices of 800 m., let's come to the American Charles Page (1812-1873), who has done serious first work in this field. The Page was able to quickly magnetization the soft iron particles and get the sounds through the magnet. His colleague, the Ceneveli physicist Auguste de la Rive (1801-1873), has developed this and addressed the German physicist Philipp Reiss (1801-1873), which we will consider as the real pre-invention of the phone.
The Reiss machine was a vibration of sound, and these vibrations shut off the electrical circuit.
Reiss was not an internationally renowned scholar. So, his work was stolen by coincidence to the American professor who gave himself to the same work. This was the son of a diction professor, and Graham Bell was born in Edinburgh on March 3, 1847. He was interested in the speech mechanism and the deaf mute, like his father. During his investigations in this area, Holmholtz's "Physiological Theory of music in terms of hearing" (1863) acquired an idea of how to sound through a Diapazon influenced by electromagnics, and electricity began to investigate.
In 1872, Bell, who emigrated to the United States and was appointed professor of Sound physiology at the University of Boston, was not involved in his deaf projects; He even married a deaf woman. So much so, in 1875, through a telegraph maneuver, a diapazit was trembling for them. One day, he used magnetic mineral fragments instead of diapazazine, and he observed that one of them had a dry sound, and he went and glued it. He was startled by a sudden inspiration. Instead of the mineral particles, he placed a membrane and connected it to an electrical circuit that changed resistance according to the membrane vibrations. Then he called his assistant who was working on the other side of the wire: "Mr. Watson, come! I need you. " Watson ran into a confused and timid manner: he heard his boss's voice on the phone.
This happened on March 10, 1876. At the time, the scholars were to qualify this invention as the most extraordinary invention in America, but it was a fact that it was too much. He wasn't working with an electric generator. It was the changes in the transmitter's magnetic field that created the electric current, passing through this wire and activating the receiver's electromagnetic power. In this case, it could not exceed 10-12 meters. Edison was the first to develop the device (1876). It increased its power by connecting a battery to the transmitter. In 1878 ′ he invented the hugnes microphone, so it was possible to amplify the sounds resulting from the vibrations of the membranes.
Such an extraordinary invention, for instance, was an unprecedented thrill to hear the voice of his friend in Boston when he was in New York; It was about events, jealousy, hatred and lawsuits. The first case was the American valued technician Elisha Gray (1835-1901). Gray, a withdrawn researcher, found the phone at the same time as Graham Bell, but unfortunately, he asked for his patent two hours later. This 120-minute delay was enough for the courts to reject their rights. Against the Bell Telephone Company, which was founded after Graham Bell's invention was proposed to The Telegraph company Western Union (1877) and rejected; So-called other inventors, developers and competitors have begun to open a pile of lawsuits, and on the one hand, they have taken unpleasant bickering and greedy bickering around the patent issues.
All the cases were in succession in favour of the true inventor. The phone was spreading steadily, the wires were reaching cities from cities. In 1880, the 35 state of America had a telephone power plant and 70,000 subscribers were recorded. When Bell died in Halifax on August 4, 1922, 17 million subscriptions in the U.S. and Canada were stopped for a minute.
In 1876, after the invention of the phone created a surprise full of admiration, what was the effect of the phonography, bring it to your eye. However, this issue did not erupt abruptly, the studies were heard among the few people. The scientists have been struggling for a long time; Even 1857 was halfway to the road. The French Edouard-Leon Scott (1817-1879), who had a modest press correction that year, produced a real recorder phonograph. It was a spike in the bottom of a cylinder, and it consisted of a membrane attached to it. When spoken or sung in front of this envelope, the voices were left vibrating on the cylinder through a pointed lube tip.
This may be the opposite of the record, which means that the pointed tip is another way to re-create the lyrics or the music through the tracks. And it wasn't easy for anyone to think about. He was a Frenchman named Charles Cros (1842-1888), who first thought of it. Cros was a poet, a humorist, and a scientist. He writes poems on the one hand, and theoretically, he was designing color photography, interplanetary transport and phonograph. The designs took place, and in 1877, he presented the plan of a device, a phonograph, in which he actually called the Academy of Sciences, "Paleophone".
Did Edison know about this work? Or we don't know if it's just a coincidence; He asked for a patent for the machine based on identical principles. They heard Edison sing the song "Mary Had a little Lamb-Mary has a little lamb," a childish song in front of this machine, and the machine said that a little bit of it was repeating it in a voice.
The fonograph of 1878 was a toy, but it was an incredible development, and it led to a pile of new inventions and inventions in today's Electrofon and Microsion Records...
How does the phone work?
The events that occur during a phone call through an electrical circuit can be sorted as follows:
1. Sound energy transforms into mechanical energy.
2. Mechanical energy transforms into electrical energy.
3. Electrical energy is posted.
4. Electrical energy on the opposite side turns into magnetic energy.
5. Magnetic energy transforms into mechanical energy.
6. Mechanical energy transforms into sound energy.
Because the oscillation rate of the vibrations in the conductivity of the electricity pulses is more than several hundred thousand times more than the speed of the air span (200-300 thousand km/h), the telephone speakers, despite the distance between them, are facing Feel. The phone system does three main missions. Provides conversation communication between two subscribers and generates voice signals, calling between subscribers, busy dialing. These operations are done manually on non-automatic phones.
The following are the main parts of a phone device:
1. Audio Receiver (microphone),
2. Microphone current source,
3. Audio transmitter (headphone),
4. Invocation and calling schemes,
5. Turn on and off the switches,
6. Call dial.
Telephone devices connected to manual and automatic power plants are different from each other. Each one of the above parts is available. The handset's voice translates to electrical energy and electrical energy. When the handset is removed on the automatic phone device, there is a switch that opens the circuit and the numerer on the front. When the telephone handset is removed, the power circuit between the telephone and the power plant is established. Tone tone is heard from the handset. When the number 6 is dialed, for example, the electrical circuit is switched on and off six times. The power-off circuit is counted as a signal to the circuit.
It is not necessarily the form of speech. The computers placed in local power plants make the distribution by selecting the number of signals sent to the terminals in the form of analog telephone, digital phone, fax, teleks, television information processing. Thus, in addition to telephone conversations, television, facsimile pictures and text, telex, computer operations are carried out as fast and high quality.
Communication lines: Communications are a wide variety of possibilities. These:
1. Two-wire analog radio signal line (1 speech).
2. Anolog Radio relay Link line (30 speeches).
3. Digital radio relay Link Line (1920 speech).
4. Multi-spoke coaxial cable line (7680 speech).
5. fiberoptic Cable Line (10,000 speech and above).
6. Communication satellites line (20,000 speech).
Two-wire speech circuits are not used outside the urban distribution system because losses in distant distances have increased and the number of channels is limited. Communication systems are very advanced in terms of capacity and quality with the advantage of radio broadcasts. Phone conversations can be performed both directly as analog signals and after the conversion of this analog signal into a digital signal. The Analog signal also has an echo problem and the signal noise level is high, and the abandoned numerical signal system has been passed.
In numerical signal systems, the analog signal is divided into slices to smooth the pals. These pulses are then encoded in the transmitter antenna ' 0 ′, ' 1 ′ are sent as digital publications. Because the coding process can be performed individually for each conversation, thousands of conversations are available at the same time from an antenna. The receiving phone, these thousands of broadcasts from the station, are analyzed again in the decoder, by turning it into a odyo signal and reaching subscribers through the central logic circuit. Encoded pals can be transmitted from the antenna as well as from coaxial cables. In coaxial cables, losses are reduced. Instead of coaxial cable, high-capacity and low-loss optical fiber cables can also be used. Digital signals encoded in the optical fiber system are transmitted to optical signals. The optical signals in the opposite power plant are first converted to electronic signals and then to the ODYO analog signal and delivered to subscribers from the local central logic circuit.
The two-wire communication system is simultaneous speaking. However, there are 30 channels in the digital radio link communication system with PALS code module. Koaks Cable Digital Radio link Communication system is capable of sending 30 megabits information at least per second, and is 1920 channels. In 1985, F. In Germany, such a system has been opened to 565 Mbit capacity per second; Another statement is available to transmit 7680 conversations or information at the same time. Fiberoptic systems are capable of 140 Mbit/sec and higher capacity. Fiberoptic communication System is the most perfect of existing systems with capacity height, ease of installation, maintenance not wanting, high quality information submission.
In summary, the names of telephone exchanges are: Electromechanical telephone power plant, electronic telephone power plant, automatic telephone power plant, intercity telephone power station, transit telephone power plant, semiconductor telephone power plant, semi-automatic There are various types of telephone power plant, local telephone power plant... (1994).
The biggest benefit the phone provides in the exercise is the rapid way of the reporter. With fiberoptic, coaxial cable and electromagnetic pathways, the phone calls made from satellites are connected to every corner of the world. The channel capacities of telephone systems are increasing every day. Increases in the number of channels make the phone even more practical. One of the major developments between telecommunications is the emergence of a cordless phone. Shortwave radio receiver-transmitters are connected to the normal phone system, the possibility of speaking on the move has emerged. As with this system, there is a seamless connection between the regions, so long-range journeys can instantly search for where they want.