Cork Institute of Technology
Higher Certificate in Engineering in Electronic Engineering – Award
(NFQ - Level 6)
Autumn 2006
Analogue Electronics
(Time: 3 Hours)
Instructions
Answer Question 1 [28 marks] and any four
other questions [Each 18 marks].
Maximum available marks is 100.
Examiner: Mr. T.Connolly
Mr. J. Berry
Dr. R. O Dubhghaill
Q1. (a) Draw circuit diagrams for each of the following.
(i) op-amp differentiator.
(ii) 3 input-summing amplifier.
(iii) Common emitter amplifier
(iv) Non-inverting op-amp amplifier.
(v) Op-amp. peak detector [10marks]
(b) Draw the circuit diagram of an AM demodulator. Explain in detail the operation of the
circuit. [10marks]
(c) Draw a circuit diagram of a series transistor voltage regulator. Compare and contrast this
with the simple zener diode regulator. [8marks]
Q2 (a) Compare A.M. and F.M. in terms of the following:.
(i) Bandwidth (ii) Ease of demodulation (iii) S/N ratio [3marks]
(b) Draw suitable waveforms to illustrate A.M. and show how the depth of modulation m can
be obtained using the waveforms [5marks]
(c) Draw the block diagram of an A.M. superheterodyne receiver and briefly explain the
function of each block. [8marks]
(d) For A.M. explain the term Image Frequency (I.F.). If the I.F.frequency is 470 kHz and the
wanted carrier frequency is 1000KHz, calculate the image frequency. [2marks]
Q3. (a) Draw the small signal equivalent circuit of a bi-polar transistor. Explain each
component in the circuit. [4marks]
(b) Draw the circuit diagram of an emitter follower.
[3marks]
(c) Draw the small signal equivalent circuit of the amplifier in part (b) [3marks]
(d) Using the circuit in part (c), derive the equations for input resistance and voltage gain of the
circuit in part (b) [8marks]
