Experiments Included:

  • Study the Working of Polarity Protection Circuit
  • Study the working of Voltage Dropper / Hook Detection Circuit
  • Study the working of Ringer Circuit
  • Study the working of Keypad Circuit
  • Study the Working of TONE/PULSE Dialer Section
  • Study the Working of Speech Circuit
  • Study the Telephone Trainer Switched Faults

Basic working principle of a telephone is very important in telecom. This trainer helps students understand the functional working of an actual telephone. It provides in depth explanation of the different sections of a DTMF Telephone. Test points are provided to observe different signals which help in understanding different blocks of a Telephone.


  • Required Circuits Tested
  • Each Section Clearly Marked for Input and Output
  • Polarity Protection
  • Monolithic Dialer, Ringer and Driver
  • Each Section Clearly Marked for Easy Understanding

Technical Features:

  • Operation: Stand Alone
  • Input Power: From Telephone Line
  • Handset: Handset connection Port (RJ-11)
  • Dial Pad: 4×4 Matrix Key Pad
  • Dialer Section: DTMF (Tone) and Pulse Dialing Redial upto 32 digits with Hook Switch detection
  • Indication: Line On / OFF Pulse Dialing Indication, Tone Dialing Indication
  • Control: Ringer Volume Control
  • Dial Pulse Ratio: 66 to 33 % Make / Break Ratio (approx.)
  • Test Points: To observe various signals / voltages to understand the working of Telephone
  • Switch Faults: 4 Nos.
  • Interconnections: 2 mm gold plated pins

Accessories: Power cord, Experiment Manual and 2mm patch cords