On March 10, 1876, in Boston, Massachusetts, Alexander Graham Bell discovered the telephone. Alexander Graham Bell, assisted by Thomas Watson, made the phone itself from a wooden stand, funnel, cup of acid, and several copper wires. But with this simple tool Alexander Graham Bell can make calls to his colleagues in another room – “Mr. Watson, come here, I want you!”. Bell filed a patent application just hours before his competitor, Elisha Gray. What’s more, even though no one really built a functioning telephone, Bell made his phone operate three weeks later using the ideas outlined in Gray’s Notification of Discovery, a method Bell did not propose in his own patent. Besides being curious for now, the telephone story is a story of discovery itself. Bell develops new and original ideas but does so by building on older ideas and developments. Bell succeeded specifically because he understood acoustics, the study of sound, and something about electricity. Other inventors know electricity well but are a bit acoustic. Therefore, the telephone was a joint achievement among many pioneers, even though the credit and prizes were not shared equally. It is also often a story of discovery. The telephone comes from the Greek word tele, meaning from a distance, and the telephone, which means sound or voice. In general, a telephone is any device that transmits sound remotely. A telephone cord, megaphone, or talking tube can be considered a telephone instrument but for our purposes, it is not a telephone. It transmits sound mechanically and not electrically. Talk is a touching sound. Speaking produces acoustic pressure. Talking with a telephone cord, for example, makes the channel vibrate, causing sound waves to move from one end of the channel to the other. The telephone as a comparison, reproduces sound using electricity.
The standard dictionary defines the telephone as a tool to reproduce sound, especially sound, over very long distances, using electricity; consists of the transmission and reception of instruments connected by a channel or cable that conducts electric current. Electricity operates telephones and modern telephones use electret microphones for transmitters and piezoelectric transducers for receivers but the principles described are the same. Sound waves captured by an electret microphone cause a thin plastic diaphragm coated with metal to vibrate, producing variations in the electric field across a small air gap between the diaphragm and the electrode. Piezoelectric transducers use materials that change the mechanical pressure of the sound waves above to vary the electrical signal.Telephone history begins at the beginning of human history. Humans always want to communicate from afar. People have used smoke signals, mirrors, forest drums, post pigeons and semaphores to send messages from one point to another. But the telephone is something new. Some say Francis Bacon predicted the telephone in 1627, but his book, New Utopia only depicts a long tube. Real telephones cannot be found until the age of electricity begins. And even then it seems unwanted. The electrical principles needed to build a telephone were known in 1831 but it was only in 1854 that Bourseul suggested transmission speak electrically. And it wasn’t until 22 years later in 1876 that the idea came true.
While Da Vinci predicted a flight and Jules Verne imagined space travel, people didn’t wake up for centuries dreaming of calling. How could it be? With a little knowledge of electricity, let alone the idea that it can bring conversation, how can anyone dream of the future of the telephone? Who in the fifteenth century imagined a payphone in the corner or a fax machine on their desk? You don’t have it, goals that are easily visualized among people like powered flights, producing an inventor who works for years to realize a common goal. The development of reverse telephones is a series of events that are not connected, mostly electricity, some unintentional, which allows telephones. I will discuss just a few. bThere are many ways to communicate remotely. I have reproduced a good color diagram showing the Roman alphabet, the international flag code, Morse Code, and semaphore signaling.In 1729 the British chemist Stephen Gray transmitted electricity through wires. He sent power nearly 300 feet above the brass wire and moistened thread. An electrostatic generator supports the experiment, one charge at a time. A few years later, the Dutchman Pieter van Musschenbroek and the German Ewald Georg von Kleist in 1746 independently developed a Leyden tube, a kind of battery or condenser to store static electricity. Named after the city of discovery in the Netherlands, the jar is a glass bottle coated with tin or tin. Glass is sandwiched between sheets of metal that store electricity; Strong cargo can be stored for several days and transported. Over the years, this jar has been used in countless experiments, lectures and demonstrations.
In 1753 the author of doctor Charles Morrison, suggested in The Scot’s Magazine that electricity might send a message. He thought of the scheme of using separate cables to represent each letter. The electrostatic generator, he argues, can stir each line in turn, pulling a little paper with a static charge at the other end. By noting which paper letters are interested, someone might spell the message. Requires a dozen cables, the signal is emitted one or two miles. People work with telegraphs like this for decades. Experiments continue slowly until 1800. Many inventors work alone, misunderstand previous findings, or spend time to produce results that have been achieved. The Balky electrostatic generator generates static electricity by friction, often by turning the skin on the glass. And while static electricity can make hair stand up or throw sparks, it can’t provide energy to do things that are truly beneficial. Inventors and industries need a reliable and sustainable flow. In 1800 Alessandro Volta produced the first battery. The main development, Volta batteries provide sustainable low-power electricity at high costs. Chemically based on, like all batteries, batteries are increasing rapidly and becoming a source of electricity for further experiments. But while batteries become more reliable, they still cannot produce the power needed to work the engine, power the city, or provide heat. And even though batteries will work with telegraph and telephone systems, and still do, voice transmission requires understanding two related elements, namely electricity and magnetism. In 1820 the Danish physicist Christian Oersted demonstrated electromagnetism, a critical idea needed to develop electric power and communicate. In a famous experiment in the University of Copenhagen’s classroom, Oersted pushed a compass under a live electric cable. This causes the needle to turn from pointing north, as if acted on by a larger magnet. Oersted discovered that an electric current creates a magnetic field. But can a magnetic field produce electricity? If so, a new source of strength beckons. And the principle of electromagnetism, if fully understood and applied, promises a new era of communication
In 1821 Michael Faraday reversed the Oersted experiment. He gets a weak current to flow in a wire that rotates around a permanent magnet. In other words, the magnetic field causes or induces an electric current to flow in the nearest wire. By doing that, Faraday has built the world’s first electric generator. Mechanical energy can now be converted into electrical energy. Is that clear? This is a very important point. The simple act of moving a hand causes the current to move. Mechanical energy becomes electrical energy. Even though in many years, dynamo-powered turbines will allow the flowing water or burning coal to produce electricity. Have a river or dam? Water rotates a turbine that turns a generator that generates electricity. The more water you have, the more generators you can add and the more electricity you can produce. Mechanical energy becomes electrical energy. Faraday worked through various electrical problems in the next ten years, finally publishing the results on induction in 1831. In that year many people produced electric dynamos. But electromagnetism still requires understanding. One must show how to use it to communicate