Electronics for telecommunications
Code
DL 2543
Specifications
Quantity
PWM-PPM MODULATOR-DEMODULATOR – didactic equipment with panels made in metal case with bench
support and the electrical scheme on the front panel. The board must consist of a complete Modulator /
Transmitter / Receiver / Demodulator chain, programmable to operate with pulse width modulation or pulse
position modulation
Technical features:
The board must include the signal and timing generator and a testing tone generator, so that it is possible to
perform even complex exercises with a minimal help from external equipment. Sampling frequency variable
with continuity around 8 kHz. Band of the input analogue signal: from 340 to 3400 Hz.
The panel must contain the elements that are necessary to carry out, with suitable
connections, a PWM modulation/demodulation system and a PPM modulation/demodulation system.
The panel must completed of timing generator necessary for the operation of the circuits and of auxiliary
devices that make the use of the panel itself simple and rational.
These auxiliary devices consist in a test sinusoidal tone generator with fixed frequency and variable amplitude
and in a simulator of transmissive medium equipped with a generator of artificial noise, adjustable in
amplitude to allow a realistic experimentation.
The panel must planned according to rigorous standard for what concerns the safety of people and of the
equipment itself. For what concerns the protection of the circuits against the wrong connections and the
overloads, that the panel shall be protected against accidental inversions of the supply and against shortcircuits towards ground of the measure terminals.
With this panel it must be possible to perform the following exercises:
• PWM and PPM modulation and demodulation procedure
• Performance of PWM and PPM systems with respect to the transmission quality in presence of disturbances,
attenuation, noise
• Relationship between transmitted signal band and sampling frequency; considerations on the band occupied
by the modulated signal
• Study of the PWM modulator
• Study of the PPM modulator
• Study of the PWM demodulator
• Study of the PPM demodulator
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Code
Specifications
Quantity
• Noise effects on the transmission
• Sampling frequency and transmission quality
It must be mounted on an insulated didactic module, it must show a schematic diagram and 2 mm terminals
for the electrical connection
The board must be supplied complete with a set of stackable, plug-in cables of suitable lengths and colors and
with a training manual. Power supply: ± 15 Vdc, 100 mA
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