History of phone
Eighth centuryEuropean phonehtmlThe term is born very early
1854 inventor Antonio Muzi
Inventor of phone Antonio Muzi
Invented the basic equipment similar to phone
Connect two cup-shaped handsets with a thin string Come to
The caller only needs to speak to the cup mouth
The other end of the cup faces the ear and you can hear the sound coming from the other party
This simple device uses the principle of load vibration of sound in the air
to realize a simple message
1860 German scientist Johann Philipp Reis created the prototype of Reis phone
. Later, with the continuous improvement of technology
electromagnetic device telephone switch phone sender was then developed
. By 1904, about 3 million people in the United States relied on manual telephone switch connected
1877. In the first time, the telephone was used in China in
1822. In February 21822, the Denmark Dabei Telegraph Company established a telephone clearinghouse on Shanghai Concession and started a commercial telephone business.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ , a large turntable is placed in front of the phone
So how does this phone perform dialing operation?
According to the encyclopedia, this rotary dial is also called pulse dialing
pulse dialing is also called loop disconnection dialing
2 The rotary dial in the base interrupts the line current by repeatedly but very briefly disconnecting the line current by 1 to 10 times. When the handle is placed on the bracket, the switch permanently disconnects the line and the telegraph battery.
I don’t know if you understand
Simply put,
In the phone turntable, each number represents a pulse
1-9 There are 9 pulses in the number, and 0 also represents a pulse
0 represents the number 10, so there are 10 in total. Pulse
When you press 2, fluctuate to the pointer position and then release
At this time, 2 pulse signals are transmitted to the internal switch
That is to say,
When you need to dial the 10086 call
You just need to press 10086 in turn to the pointer position
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- tml0 This rotary dialing phone is gradually eliminated
Digital key phones enter people's lives
With the development of mobile networks
Later, smartphones appeared, and until today
Our mobile phones can not only make phone calls, but also implement the Internet function.
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