ANALOG TO DIGITAL COMMUNICATION

1. Pulse Modulation and Demodulation (PAM, PWM & PPM)                               [TOC]

PAM - PPM- PWM MODULATION & DEMODULATION TRAINER [VCT - 01]

         PPM- PAM- PWM are the basic pulse modulation techniques. The trainer provides complete set up to the students for performing experiments on these techniques. They can study Sampling, Pulse Modulation, Demodulation & Signal reconstruction process. Separate circuits are provided for each techniques.

Features :

• PAM- PPM- PWM Modulation and Demodulation Techniques, using Natural and Flat-top Sampling.

• Analog Sample, Sample and Hold and Flat-top outputs.

• Selectable 2 different sampling pulse frequencies on board.

• On board Sine wave generators.

• Voice communication using dynamic microphone and speaker

• On Board Filter and AC Amplifier

• Functional blocks indicated on board mimics

• Input- Output and Test points provided on board.

• Built in DC Power Supply

• Fully documented operating Manual

1. Pulse Amplitude Modulation

2.  Pulse Width Modulation

3.  Pulse position Modulation 

On board Sampling 

Frequencies (Pulse)       : 15.5 KHz, 31.2 KHz

On Board Generators     : 1) Sinewave 1KHz & 500Hz Tolerance ±5% (Gain Adjustable)

Low Pass Filter             : 4th Order BW Filter

Voice Communication    : Voice Link using dynamic mic & speaker

AC Amplifier                  : With Adjustable Gain control

Interconnections            : BS2 Sockets.

Power                           : 230V ±10%, 50Hz

   Accessories                  : Line cord, Manuals, Set of Patch cords, Microphone, Head phone

    Experiments Include:

1. Study of Pulse Amplitude Modulation using Natural and Flat Top sampling

2. Study of Sample, Sample & Hold, and flat top output in pulse Amplitude Modulation

3. Study of Pulse Amplitude Demodulation with sample Sample & Hold and Flat top modulating outputs.

4. Study of Pulse position modulation using AC (sinewave) modulating signals.

5. Study of Pulse Position Demodulation

6. Study of Voice Communication using PAM, PPM,& PWM Techniques.

    2.TIME DIVISION MULTIPLEXING PAM MODULATION-DEMODULATION [VCT-02]   [TOC]

         This trainer provides all necessary Inputs and connections for students to study Pulse Amplitude Modulation/Demodulation techniques. Time Division Multiplexing and Demultiplexing of Signals and Signal Reconstruction.

Features:

• Crystal controlled clock

• On-board Sine Generator (Synchronised)

• On-board Pulse Generator

• 4 Analog input channels Sampled and Time division Multiplexed

• 4 Channel demultiplexer

• Generation of Clock at receiver by PLL system

• 4th Order Butterworth L.P Filter.

• Built-in Power supply

• Crystal Frequency                      : 6.1 MHz

• Analog Input Channels                : 4

• Multiplexing                               : Time Division Multiplexing

• Modulation                                 : Pulse Amplitude Modulation 

• On-board Analog Signal              : 250Hz, 500 Hz, 1 KHz, 2 KHz(SineWave synchronised to sampling pulse) Adjustable Amplitude and separate carryable DC level

• Sampling Rate                            : 16 KHz/ channel

• Sampling Pulse                          : With Duty cycle 50%.

• Clock Regeneration at receiver     : Using PLL Low pass filter

• Cut-off Frequency                       : 3.4 KHz

• Test Points                                : 52

• Interconnections                         : 4mm Sockets

• Power                                        : 230V ±10% 50Hz

• Accessories                               : Manuals, set of patch cords, Line cord

   Experiments that can be performed:

1.  Study of Pulse Amplitude Modulation technique

2.  Study of Time Division Multiplexing and Demultiplexing

3.  Study of PLL as Freq. Multiplier to generate clock from synchronous signal.

4.  Study of three Modes of operation to regenerate original signal.

   a) 3 Connections between transmitter and receiver (clock, sync, information)

   b) 2 Connections (information, sync) Clock regenerated at receiver.

   c) 1 connection (information only). Clock and Sync derived at receiver

   Each Rs. 8,500.00 + EXCISE DUTY @ 16% +SALES TAX @ 4%.

    3. AMPLITUDE MODULATION & DEMODULATION MODULE (VCT-03)                        [TOC]

    This module is used to study the Amplitude Modulation & Demodulation technique, for the students.

• Amplitude modulating circuit.

• Outputs and Inputs are provided in the proper terminals.

• Carrier and modulating signals are provided in the unit with frequency variable.

• Demodulating circuit

• Used along with fibre optic Analog link for

  i.  Generation of AM Signal.

  ii. Transmission of AM Signal through Fibre optic Analog link. 

  iii. Demodulating the AM Signal.

  Each Rs. 6,000.00 +EXCISE DUTY @ 16% +SALES TAX @ 4%

4. AM SUPER HETERODYNE RECEIVER [VCT-06]                                                      [TOC]

• Testpoints to study different waveforms

• Provide Audio Power amplifiers & Speaker in the unit

• In-built DC Power Supply

• Discrete Circuit to study superheterodyne receiver

   Technical Specifications :

• Intermediate Frequency : 455 KHz

• Input circuits : i. RF Ampr. ii. Mixer. iii. Local Oscillator. iv. IF Amplifier - 1. v. IF amplifier - 2. vi.IF Amplifier - 3.

• Tuning : Ganged tuning

• Detector : Diode detector (DSB)

• Audio Output : Audio Amplifier with speaker

• Receiving media : Antenna

  Each Rs. 3,000.00 + EXCISE DUTY @ 16% + SALES TAX @ 4%

 5. PULSE CODE MODULATION/DEMODULATION [VCT-07]                                        [TOC]

     Features :

• In-built sinewave generator

• Provide transmitter and receiver in the same unit

• Test points to study different waveforms

• Functional block indicated by mimic diagram

• In-built DC Power supply

• Crystal Frequency : 6.14 MHz

• Onboard Generator : 1. Sinewave generator (250Hz) 2. Variable DC Source

• Sampling Frequency : 8 KHz

• LPF : Fourth order butterworth filter