The research on long-distance sound transmission in Europe began in17th century. Robert hooke, a famous British physicist and chemist, first put forward the suggestion of long-distance voice transmission. 1796, Hughes put forward the method of transmitting voice information through microphone relay, and called this communication method-telephone, which has continued to this day.
1832, American doctor Jackson told the passengers about the principle of electromagnet on a mail ship sailing in the Atlantic Ocean. Among the passengers, American painter Morse, 4 1 year-old, was deeply attracted. At that time, the French signal system could only send miles of information visually. Morse dreamed of using electric current to transmit electromagnetic signals and instantly send information thousands of miles away. Since then, Morse's life has undergone fundamental changes.
Morse's inspiration comes from the fact that the current flowing in the conductor will spark in generate when the conductor is suddenly cut off: if the current is cut off as a signal, the current is turned on without spark as another signal, and the current is turned on for a long time as a signal, these three signals can represent all letters and numbers together, and words can be transmitted to a distance through the current. 1837, Morse finally designed the famous Morse code, which used different combinations of "dot", "dash" and "interval" to represent letters, numbers, punctuation and symbols. 1844 On May 24th, Morse personally operated the telegraph in the meeting room of the Federal Supreme Court of the Capitol in Washington. With a series of "dot" and "dash" signals, Baltimore, 64 kilometers away, received the world's first telegram composed of "beep" and "click".
Who invented the telephone?
At present, the recognized inventor of the telephone is Bell, who applied for the telephone patent right in the US Patent Office on February 1876. In fact, just two hours after he applied, a man named E Gray also applied for a telephone patent.
Before the two of them, many people in Europe were already doing ideas and research in this field. As early as 1854, the telephone principle was conceived by the Frenchman Bausal, and the idea was repeated by the German Rice six years later. The principle is that two thin metal sheets are connected by wires. When one side makes a sound, the metal plate vibrates and becomes electricity, and the electricity is transmitted to the other side. But this is just an idea. The problem is the structure of microphone and receiver, and how to convert the mechanical energy of sound into electrical energy and transmit it.
At first, Bell used electromagnetic switches to form on-off pulse signals, but this method obviously didn't work for such high-frequency sound waves. The final success came from an accidental discovery. 1June 2, 875, in an experiment, he connected a metal plate to an electromagnetic switch. Unexpectedly, in this state, the sound becomes a wonderful current. According to the analysis principle, the original metal sheet induces current in the connected electromagnetic switch coil due to sound vibration. Now it seems that this principle is known to all students who have studied junior high school physics, but it is undoubtedly a very important discovery for Bell at that time.
Gray's design principle is different from Bell's, which uses the resistance change of the liquid inside the microphone, while the receiver is exactly the same as Bell's. 1877, Edison obtained the invention patent of carbon particle microphone. At the same time, many people have made various improvements to the way the telephone works. The patent dispute is complicated, and it didn't come to an end until 1892. One of the reasons for this situation was that the largest Western Union telegraph company in the United States bought the patents of Gray and Edison at that time and confronted Bell's telephone company. Due to the long-term patent dispute, the two sides reached an agreement. Western Union Telegraph Company fully recognized Bell's patent right and never set foot in the telephone industry again. In exchange, it shared 20% of Bell's income in 17.