Basic Electronics Practical

COURSE TITLE/CODE:

BASIC ELECTRONICS COURSE CODE/PIP 008

Experiment 1 Title:

Physical Identification Of A PN-Junction Diode And Test Of Its Functionality. Objective:

At the end of the experiment the student should be able to identify pnjunction diode physically and test for its functionality.

Background Theory: The pn-junction diode is formed by growing one crystal, (it must be continous) of semiconductor, material and doping separate but adjacent layers of it with the appropriate impurities. At equilibrium, a depletion layer is formed at the junction that is void (depleted) of loosely held charge carriers. When conducting leads are attached to a pn-junction, the device exhibits a useful characteristics and is called a PN-junction diode.

Apparatus: 1. Multi-meter 2. Semiconductor diode type IN4007.

Diagram:

P

N

P

+++ -+--+++ -+--+++ -+---

P

N

Procedure: Identifying the PN-junction diode physically

N

1. The Semiconductor diode IN4007 looks cylindrical in shape 2. Identify the cathode by locating the end with a white stripe around it as shown in the diagram 3. The other end with no white stripe is the anode 1. 2. 3. 4. 5. 6. 7. 8.

Test of Functionality using a multi-meter Switch on the multimeter Select the semiconductor test mode on the digital multimeter Connect the red probe to the anode as earlier identified. Connect the black probe to the cathode Observe what happens Connect the black probe to the anode Connect the red probe to the cathode Observe what happens

Results: Resistance reading Forward bias Reverse bias

Experiment 2 Title:

Operation Regulator

Of

Zener

Diode

As

Voltage

Objective:

At the end of the experiment the student should be able to understand regulation in power supplies and measurements in linear voltage regulators.

Background Information:

The zener diode is the basic component in regulation circuits. The zener diode is a diode operated in the reverse breakdown region. It is made from a heavily doped PN junction and reverse breakdown voltage or zener voltage is specified by the manufacturer.

Apparatus: TPS 3321, Multimeters, Banana wires. Procdure: 1. Implement the circuit as shown above 2. Turn the trainer 3. Change Vi and fill the following table

Diagram: IN4001 Meter 1

1 K𝛺

Vi

Vo

Results: t Vi Vo Vi Vo Sv

1 7V 4.33

2 8V 4.42

3 9V 4.49

4 10V 4.52

Meter 2

Exercises: Vo(t) = Vo(t+1) – Vo(t) Vi(t) = Vi(t+1) – Vi(t) Plot graph of Vi against Vo Calculate the regulation coefficient for each column Sv = Vo/ Vin Determine the zener voltage State your observations Draw your conclusions

Experiment 3 Title:

Determination Of Transistor (NPN) Characteristic Curve Objective:

At the end of the experiment the student should be able to measure and draw the output characteristic curve of an NPN transistor.

Background Information:

Bipolar junction transistors have base (B), an emitter (E) and a collector (C) as its electrodes. However, when the transistor is connected such that the emitter is common to the base-emitter side and the collector-emitter output side, then the configuration is said to be common emitter configuration. The output or collector characteristics plots of the output current (Ic) versus output voltage (Vce) for fixed values of input current, Ib.

Apparatus: TPS 3321and multimeter. Procedure: 1. 2. 3. 4.

Connect the circuit as shown above. Output characteristics Adjust the input resistance R1 and R2 until Ib = 0µA initially. Turn R3 to increase Vce in steps of 1V, starting from 0V to 10V, measure and record corresponding values of Ic using table1. 5. Follow the procedure in step 1 and set Ib =20µA to 80µA for each fixed value of Ib, repeat step 2 and complete the table.

Diagram: 0 – 30mA R3 100𝛺 0 – 100mA R2 1M𝛺 A

A 10V

Ic

Ib R1 100K𝛺 Vce

5V

Results: Table 1 Ib(µA) Vce(V) 0 1 2 3 4 5 6 7 8

0

20

40

60

Experiment 4 Title:

Output Characteristics Of A Common Source Fet Objective: At the end of the experiment the student should be able to understand the operation of a field effect transistor and draw its output characteristics.

Background Information:

The field effect transistor is a three terminal unipolar device, the FET is a voltage controlled device used in digital and analogue circuits for control and switching. It has three terminals, the Gate, the Drain and the Source. A plot of the drain current against the gate – source voltage yields the output characteristics.

Apparatus: TPS 3321, Voltmeters and Ammeters. Procedure: 1. 2. 3. 4.

Connect the TPS 3321 trainer to the power supply and the power supply to the mains. Implement the diagram shown above Turn on power supply Change VGG according to the following table and register the measured values of V GS, VD and VS

Diagram: + 12V 5.1 K VG

1M

VGG

1K

Results: No

1

2

3

4

5

6

7

8

9

10

11

VGG (V) VG (V) VD (V) VS (V) VGS (V) ID (mA) IS (mA) VDS (V)

3

2.5

2

1.5

1

.5

0

-0.5

-1

Exercises: Calculate VGS for every VGG value according to the following formulae: VG = VGG VGS = VG - VS ID = (VDD – VD)/ RD VGS, = VS/RS Calculate VPO and IDSS of the component. Plot ID against VGS.

- 1.5

-2