Linear and non-linear processes - Signals, Processes, and Systems - page 219

Exercises on Chapter 7
Exercise 1

Using DASY Lab design a test circuit which is as simple as possible by means of which
you can demonstrate and measure the linearity or non-linearity of a system or process.

Exercise 2

What would be the possible consequences of the non-linear behaviour of the transfer
media „open space“ and „cable“?

Exercise 3

If a sequence of rectangular pulses are connected to the input of a long cable a distorted
signal (a kind of „melted rectangle“) appears at the distant end of the cable.

a) What are the causes of these distortions?

b) Are non-linear distortions or linear distortions involved?

Note: You can simulate a cable as a chain of simple lowpass filters using DASY Lab
(see Illustration 116)

Exercise 4

How does the sum of two sinusoidal oscillations of the same frequency and amplitude
change depending on the mutual phase displacement? Design a small test position using
DASY Lab .

Exercise 5

Explain the way the amplitude spectrum of two consecutive pulses in Illustration 126)

arises. How do the zero positions of the amplitude spectrum depend on the time interval
between these

δ−

δ− pulses?

Exercise 6

Using DASY Lab design a voltage frequency converter VCO according to Illustration 131
which with an input voltage of 27mV produces a sinusoidal output signal of 270 Hz. The
characteristic should be linear.

You will need a special setting of the „Generator“ module and an input circuit to control
this generator.

Exercise 7

What advantages does frequency coding of measurement values by means of VCO have
in telemetrics?

Exercise 8

Check the following thesis using DASY Lab : the sequence of linear processes in a linear
system can be changed round without changing the system.