# ELA125 ELE22AI Tutorials(1)

```TUTORIAL COMPONENTS
ELA125A(B) Tutorials:
Unit 1: Analogue design using BJT amplifiers: Chapter 5 - Problems: 1 to 56.
Reference: Floyd TL. Electronic devices: Conventional Current Version. 10th ed, Global
Edition. London: Pearson Education, Ltd; 2018. 928 p. ISBN-13: 978-1292222998;
ISBN-10: 9781292222998.
Unit 2: Analogue design using OP-amplifiers: Chapter 12 - Problems: 1 to 56.
Reference: Floyd TL. Electronic devices: Conventional Current Version. 10th ed, Global
Edition. London: Pearson Education, Ltd; 2018. 928 p. ISBN-13: 978-1292222998;
ISBN-10: 9781292222998.
Unit 3: Signal generators and waveform-shaping circuits: Chapter 16 - Problems:
1 to 22. Reference: Floyd TL. Electronic devices: Conventional Current Version. 10th
ed, Global Edition. London: Pearson Education, Ltd; 2018. 928 p. ISBN-13: 9781292222998; ISBN-10: 9781292222998.
Unit 4: Frequency response: Chapter 10 - Problems: 1 to 44. Reference: Floyd
TL. Electronic devices: Conventional Current Version. 10th ed, Global Edition. London:
Pearson Education, Ltd; 2018. 928 p. ISBN-13: 978-1292222998; ISBN-10:
9781292222998.
Unit 5: Feedback amplifiers: Chapter 15 - Problems: 15.1 to 15.29. Reference:
Storey N. Electronics: A system Approach. 6th ed. New Jersey: Pearson Education, Inc;
2017. 864 p. ISBN-10: 1292114061; ISBN-13: 9781292114064.
Selected examples will be illustrated and worked out during theoretical sessions
Unit 1: Students (in class) to do in groups of five (5) - Problems: 3, 4, 7, 9,
13, 16, 19, 20, 30, 35, 36, 37, 38, 39, 49, 50, 51, 52
Unit 2: Students (in class) to do in groups of five (5) - Problems: 1, 2, 3, 6, 7,
8, 9, 10, 12, 13, 14, 15, 18, 19(a); 21(c); 22; 25; 27; 28; 29(a); 30(d); 33;
35; 37; 39(a &amp; b); 40(b); 52; 54; 55.
Unit 3: Students (in class) to do in groups of five (5) – Problems: 5; 7; 8; 9;
12; 13; 14; 16 (PUT); 19; 22; Twin-T;
Unit 4: Students (in class) to do in groups of five (5) – Problems: 1, 2, 3, 4,
5, 6, 7, 12, 14, 21, 26, 29, 35, 42
feedback
R
R
2C
C
U1
C
Vo
OUT
R/2
+
R1
R2
Figure 1: Twin-T Oscillator
A Twin-T oscillator circuit is designed to produce a 1kHz sinusoidal
output signal for use in an electronic circuit. If an operational
amplifier with a gain ratio of 200 is used. Select R = 10 kΩ.
From Figure 1, determine C (nF):
2
What is the E24 standard value of C as determined in the preceding question
(nF):
2
From Figure 1, determine the centre Tee-leg capacitor (nF):
2
What is the E24 standard value of the centre Tee-leg capacitor as determined
in the preceding question (nF):
2
From Figure 1, determine the R(leg) (kilo-ohms):
2
What is the E24 standard value of the R(leg) as determined in the preceding
question (kilo-ohms):
2
From Figure 1, determine the R1 (kilo-ohms):
2.
From Figure 1, determine the R2 (kilo-ohms):
2.
From Figure 1, determine the final trim potentiometer for R(leg) (kilo-ohms):
R(leg) trim potentiometer = next E24 value of R(leg) equal or greater
than R/2 = ?? √√ 2
+15 V
R3
VG
PUT
R4
-15 V
C1
0
VCC-
R1
2
-
V-
4
U8
Ri
B1
3
+
B2
Vout
6
5
7
R2
V+
OUT
LF411
1
0
0
VCC+
Figure 2: Sawtooth VCO example
For Figure 2, the amplitude and frequency must be determined.
Assume that the froward PUT voltage, VF, is 1 V. Take R1 = 68 kΩ; R2
= 10 kΩ; Ri = 100 kΩ; R3 = R4 = 10 kΩ; and C1 = 0.0047 uF.
For the circuit of Figure 2, determine Vp (V):
2
For the circuit of Figure 2, determine the PUT trigger voltage (V):
2
For the circuit of Figure 2, determine the amplitude (V):
2
For the circuit of Figure 2, determine Vin (V):
2
For the circuit of Figure 2, determine T (ms):
2
For the circuit of Figure 2, determine f (kHz):
2
Schmitt Trigger – Integrator triangular waveform generator:
R3
C1
VCC
A1
2
-
OUT
OS1
5
4
OS2
R1
6
2
1
-
A2
uA741
+
OS1
OUT
OS2
1
6
5
7
4
3
V-
+
V-
3
uA741
V+
R2
V+
7
VEE
VEE
VCC
V1
V2
9Vdc
9Vdc
VCC
VEE
Figure 3: Figure 16-24 - Schmitt trigger – Integrator triangular
waveform generator
A triangular waveform generator is to be designed to produce &plusmn;1 V,
1 kHz output. Use a 741 OP-AMP with VCC = &plusmn;9 V. Select I1 = I2 =1
mA.
Integrator design:
For the circuit of Figure 3, determine Vi (plus/minus)(V):
2
For the circuit of Figure 3, determine ΔVo (V):
2
For the circuit of Figure 3, determine R1 (kilo-ohms):
2
What is the E24 standard value of R1 as determined in the preceding question
(kilo ohms):
2
For the circuit of Figure 3, determine t (uS):
2
For the circuit of Figure 3, determine C1 (nF):
2
What is the E24 standard value of C1 as determined in the preceding question
(nF):
2
Schmitt Trigger design:
For the circuit of Figure 3, determine R2 (kilo-ohms):
2
For the circuit of Figure 3, determine R3 (kilo-ohms):
2
f2 = Av x fp
SR = 2πfpVp
555 Timer:
VCC = 15 V
R1
2k
R2
2k
8
2
4
5
6
7
C1
U1
VCC
TRIGGER
RESET OUTPUT
CONTROL
THRESHOLD
DISCHARGE
GND
3
Vo
C2
300n
555C
1
Figure 4: A 555 pulse generator circuit
For Figure 4, determine the charging time, t1 (us):
2
For Figure 4, determine the discharging time, t2 (us):
2
For Figure 4, determine the period, T (ms):
2
For Figure 4, determine the pulse frequency, f (Hz):
2
For Figure 4, determine the pulse width, PW (us):
2
For Figure 4, determine the space width, SW (us):
2
For Figure 4, determine the duty cycle (ratio)(milli):
2
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