DSC 1030-3 Tactical Communications
Demarco Smith
DSC 1030-3 Tactical Communications - 3
Individual Work: Week 4
What were the original methods of switching telephone calls?
How does a rotary dial phone operate?
How does a touch tone phone operate?
What are some historic and modern methods used to transmit telephone signals?
The original methods of switching telephones came as soon as a public interest in the telephone arrived. This has occurred in 1877, and in less than a year after Bells original patent had been granted. The method was connected to every telephone individually and to every phone. This connection activity would become quickly complicated and harsh or impractical. Over one thousand different connections would be required to interconnect …show more content…
This had a max of eight different telephone lines. In 1892 the first set of commercial installation of automatic switching equipment using the step by step mechanism was made at La Porte in Indiana. Various calling devices were used for a number of years. Among these were lever operated pre-set devices, key sets of several types, and dials with holes in which a peg could be inserted to act as a stop for an arm which was pulled around and allowed to restore. In all the early systems, regardless of the device used, the signals generated at the calling station directly controlled the selectors. The rotary dial works on a pulse based system. The frequency of pulses is determined by the number on the dial which the caller selects. Using the manually turn dialer to a fixed angel where the finger releases it before the number arrives while spinning. While this occurs these causes the dial spin to return to the starting position.Inside the body of the phone a centrifugal governor ensures that the dial’s rotation is moderated to a constant rate, with a shaft on the governor turning a cam that opens and closes a switch contact. If the contact is open, the line’s current is stopped from flowing, thereby creating a dial pulse, while when closed, there is a constant flow of
DSC 1030-3 Tactical Communications - 3
Individual Work: Week 4
What were the original methods of switching telephone calls?
How does a rotary dial phone operate?
How does a touch tone phone operate?
What are some historic and modern methods used to transmit telephone signals?
The original methods of switching telephones came as soon as a public interest in the telephone arrived. This has occurred in 1877, and in less than a year after Bells original patent had been granted. The method was connected to every telephone individually and to every phone. This connection activity would become quickly complicated and harsh or impractical. Over one thousand different connections would be required to interconnect …show more content…
This had a max of eight different telephone lines. In 1892 the first set of commercial installation of automatic switching equipment using the step by step mechanism was made at La Porte in Indiana. Various calling devices were used for a number of years. Among these were lever operated pre-set devices, key sets of several types, and dials with holes in which a peg could be inserted to act as a stop for an arm which was pulled around and allowed to restore. In all the early systems, regardless of the device used, the signals generated at the calling station directly controlled the selectors. The rotary dial works on a pulse based system. The frequency of pulses is determined by the number on the dial which the caller selects. Using the manually turn dialer to a fixed angel where the finger releases it before the number arrives while spinning. While this occurs these causes the dial spin to return to the starting position.Inside the body of the phone a centrifugal governor ensures that the dial’s rotation is moderated to a constant rate, with a shaft on the governor turning a cam that opens and closes a switch contact. If the contact is open, the line’s current is stopped from flowing, thereby creating a dial pulse, while when closed, there is a constant flow of