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INTRODUCTION TO ELECTRONICS (BEB 11103)

S2`2015

LAB PRACTICAL 2

DESIGN A BJT AMPLIFIER

Student Name: ID: Group:

ASSESSOR’S COMMENT: MARKS:

Task No. Unit Content & Assessment Objectives Marks

Pre-Lab 1-3 4-5 Lab-R

Operation of Power Supply • To design an amplifier using BJT Transistor • To verify and test the designed amplifier • To build and test the designed amplifier • To demonstrate the amplifier operation and characteristic • To analyse and summarize the investigation in Technical Report • Practical Test

15 10 20 10 20 25

TOTAL PERCENTAGE

100

10%

Group L02-T01 L02-T02 L01-T03 Total No of Student 24 7 18 49 Tutor MOAA MOAA MOAA 1

Verified by: Subject Leader [MOAA] Prepared by: [MOAA] I hereby declare that all my team members have agreed with this assessment. All team members are certain that this assessment complies with the syllabus.

Signature: ____________________________

Date : ____________________________

HOS verification

QAS verification

UniKL BRITISH MALAYSIAN INSTITUTE

2

Objectives

1. To Investigate three different configuration of BJT amplifier 2. To verify and test the design of the amplifier 3. To analyse the percentage of accuracy between calculation and actual measurement

Pre-Lab Assignment

Derive the equations for VC, VB, VE, VBE , VCE , IC, IB and IE. for the circuit shown in Figures 4-1

through 4-3

[15 marks]

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In-Lab Activites

1. Build the Fixed Bias circuit shown in Figure 4-1 on your protoboard

2. By using the DMM, measure each of the transistor node DC voltages (VC, VB, VE, VBE and VCE)

and determine/calculate all the currents (IC, IB and IE). Claculate β and then calculate α.

3. Set Function generator to produce Sinewave signal Vp-p 10 mV. Apply the signal to the circuit

and use Oscilloscope to probe the voltage signals at Base and Emmiter.

4. Repeat steps 1 and 2 for the Emmiter Stabilised Bias circuit as shown in Figure 4-2

5. Set Function generator to produce Sinewave signal Vp-p 10 mV. Apply the signal to the circuit

and use Oscilloscope to probe the voltage signals at Base, Collector and Emmiter.

6. Repeat Step 5 for the circuit without capacitor at Emmiter.

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7. Repeat steps 1 and 2 for Voltage Divider circuit shown in Figure 4-3

8. Set Function generator to produce Sinewave signal Vp-p 10 mV. Apply the signal to the circuit

and use Oscilloscope to probe the voltage signals at Base, Collector and Emmiter.

9. Repeat Step 8 for the circuit without capacitor at Emmiter.

5

10. Record all your results in Table 4-1 Results

11. Record all your resistor biasing values as follow :

[10 marks]

[20 marks]

[25 marks]

6

LAB 2 Report

1. By using only the derived equation β and VBE (pre-lab) calculate VC, VB, VE and VCE, IC, IB and IE and compare with in-lab activity results.

2. Calculate the percentage relative error between your measured values and your calculated values. 3. Compare the phase of the probe signals at base, emmiter and collector

Fixed Bias Circuit

Emitter Stabilised Bias Circuit

Voltage Divider Bias Circuit

[20 marks]

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Practical Test 2 (Each Question carries 5 marks)

1. Draw two biasing configuration for BJT amplifier 2. Explain the function of coupling capacitor at base, collector and emitter for voltage divider BJT

configuration 3. Derive VCE for voltage divider BJT configuration 4. Explain the position of Q point in voltage divider BJT configuration 5. Compare the phase for Output and Input signals for voltage divider BJT configuration at Base,

Emmiter and Collector