Telephone Set Component(additional note)

Block Diagram Of Telephone Set

Telephone Set Component

- DTMF circuit and keypad

  DTMF (Dual Tone Multi Frequency) as the name suggest uses a combination of two sine wave      tones to represent a key.

keypad

- Tone ringer circuit

   The tone ringer drives a piezoelectric sound element that produces an electronic ring.

Ringer Circuit

- Microprocessor

  The MPU with RAM, control the function of the telephone such as number storage, speed dialing,    redialing, and auto dialing.

- Speech network
  Speech network is also called voice network or telephone hybrid which connect the microphone and  speaker to the telephone line.

Hybrid

- Line voltage regulator
  The line voltage regulator convert dc voltage receive from the local loop and convert to constant level dc supply

- Loop or Line Interface
  - A special connector on the cable, called an RJ-11 modular connector, plugs into the matching wall jack.
  - Also known as the wiring block, modular interface or telephone box.

- On/ off hook circuit
  When the handset is on hook, the hook switch is open, thereby isolating all the telephone circuitry    from the local loop.

- Speaker and microphone
- The speaker convert electrical signal received from the local loop to acoustical signal.
- The microphone convert acoustical signal in form of sound pressure wave to the electrical signal.

Microphone and Speaker

                                                          Telephone Set Component