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EXPERIMENT NO #1

OBJECT:

Introduction of the basic electronic components with checking procedure.

RESISTER

A resister is manufactured with a specific value of ohm for R. the most common resistor are carbon type are wire wound. The purpose of using a resister in a circuit is either to reduce L to a specific value or to produce a desired IR voltage drop.

TYPE OF RESISTER:

CARBON TYPE RESISTER:

CARBON TYPE RESISTERS:

This type of resistor are made of finely divided carbon or graphite mixed with a powdered insulating material. Carbon resistor are commonly available in R values 1W to 20 MW .

 WIRE WOUND RESISTERS:

In this type of construction a special type of wire called resistance is wrapped around an insulating core. They are generally for high current rating application with low resistance and appreciable power wire-wound resistor are available in power rating from 5watt to 100watt or more.

VARIABLE RESISTER:

Variable resister can be wire-wound or carbon type. A carbon control resister is often combined with a power on-off switch .Carbon control is available with a total R from 100W to 5 MW approximately. Their power rating is from ½ watt to 2w.

COLOR COOLING RESISTER:

Since carbon resister are small in size , they are color coded to mark their R value in W .the basis of this system is the use of color of numerical value. The color coding is standardized by the "ELECTRONIC INDUSTRIES ASSOCIATION" (EIA).

BLACK 0 GREEN 5

BROWN 1 BLUE 6

RED 2 VIOLE 7

ORENGE 3 GRAY 8

YELLOW 4 WHITE 9

TOLERANCE:

RED + 2%

GOLDEN + 5%

SILVER + 10%

NOCOLAR + 20%

DIODE:

A diode is a two-terminal device which conduct current only in one direction .
 
 

TYPES OF DIODE:

SEMI CONDUCTOR DIODE:

The standard symbol for a semi conductor the diode is an arrow showing the direction of hole flow and a bar.

The anode or arrow side of the symbol contains the p-type material where as the cathode or bar side has N-type material.

ZENER DIODE:

Zener diode are also called voltage reference diode. They are named after C.A.Zener.Who analyzed the voltage break down of insulator. They are silicon diodes designed for a specific reverse breakdown voltage . Silicon is preferred to Ge because its higher temperature and current capability.

Zener breakdown occurs due to braking of covalent bond the strong electric field setup in the depletion region by reverse voltage.

LIGHT EMITING DIODE (LED):

A p-n junction radiate light when current passes through the unit. For best efficiency special compound of (Ge) are used .

TRANSISTER:

A transistor is a three- layer semiconductor device.

Experiment # 2.

OBJECT:

TO become familiar with multi meter and it use in measuring the voltage, current and resistance.

APPARATUS:

D.C 9Volts power supply or battery, multi meter different type of resistance and isolator.

THEORY:

Ammeter:

An ammeter is an instrument use for the measurement of the current flowing through a circuit. Basically it is a galvanometer having an additional suitable low resistance RS , called shunt ,connected in a parallel with a coil of galvanometer. When the instrument is connected in a circuit in series, most of the current flow through shunt, and a very small fraction of it passes through the coil of galvanometer produces its deflection on a graduated scale which is calibrated to record the total current . Altering the value of shunt alter the range of the instrument the ammeter has to binding screws, one of which is marked positive and other negative to indicate higher and lower potential terminals respectively.
 
 

VOLTMETER:

An voltmeter is an instrument used for the measurement of potential difference between any two points of a circuit basically it is a galvanometer having an additional suitable high resistance R connected in series with a coil of galvanometer. when the instrument is connected in a circuit between the two points in parallel, very small fraction of the total current passes through its and the current in the main circuit remains practically an altered. The range of the instrument is altered by altering the value of the high resistance use in series with the coil. The voltmeter has two binding screw one of which is marked +ve and other –ve to indicate higher and lower potential terminal respectively.

OHM-METER:

The basic meter movement can be use to measure resistance if it is combined with a battery and a current limiting resistance. In that case ,it is known as an ohm-meter for measuring resistance the ohm meter lends are connected across the unknown resistance after switching off the power the curcuit under test. Only in that case, the ohm meter can provide current for the meter movement. Since amount of current depends on the amount of external resistance , the meter scale can be calibrated in ohms(instead of mA).

MULTIMETER:

In electronics measuring instrument, multimeter is often used. They are used measure voltage, current or resistance and also for checking the continuity. The main types of the multimeter are :
 
 
 
  CIRCUIT DIAGRAM FOR TEST CIRCUIT FOR MULTIMETER:

Because of the simplicity, compatibility and portability, the VOM is preferably and more common. The cost of a basic type of VOM is less than for DMM. Also where charge in VOM.

Or L must be checked, VOM is more convenient.most multimeter measure A.C voltage and current values the A.C variation are converted into D.C voltage internally for the meter .How ever the frequency response is generally limited to about 20 KHz or less also the input impedance is lower as compared to A.C. Voltmeter because of the rectified circuit. In order to measure the radio frequency signal voltage. A special RF meter or a RF probe is necessary.

OBSERVATION :

Measure the supply voltage : Vs = 9V

Measure the in put current : Iin = 8mA

Measure the in put voltage : Vin = 8.9V

Measure the out put current: Iout = 160mA

Measure the out put voltage: Vout = 2.2V

Measure the resistance #4 : R4 = 940W

CALCULATIONS:

Calculate the total resistance of the input circuit:

RT = Vin/ Iin = 8.9/0.018 = 0.494 KW

Calculate the total resistance of the out put circuit:

RT = Vout/ Iout = 2.2/0.16 =13.75 W

Calculate the internal resistance of supply/battery:

R = (Vs –Vin)/ Iin = (9-8.9)/0.018 =5.55W

Calculate the power dissipated across R4 :

P= (Iout )2 R4 = (0.16)2 (940)=24W

RESULT:

Total input resistance = RT = 0.494kW

Total output resistance = RT = 13.75W

Internal resistance of supply =R=5.55 W

Power dissipated across R4 = p=24W

EXPERIMENT # 3

To draw the semiconductor diode characteristic between diode voltage and diode current and calculate the load resistance (RL) induced in the measurement circuit.

Apparatus:

Variable D.C power supply or Battery , Digital voltmeter (DVM), Ammeter , Semiconductor diode , Load resistance and switch (isolation).

THEORY:

 SEMI CONDUCTOR DIODE:

The standard symbol for a semi conductor the diode is an arrow

showing the direction of hole flow and a bar.

The anode or arrow side of the symbol contains the p-type

material where as the cathode or bar side has N-type material.

OBSERVATION :
S.NO
VS(Volts)
ID (mA)
VD (Volts)
RL kW
1
2
1.0
0.60
1.4
2
4
2.5
0.62
1.352
3
6
4.5
0.64
1.1911
4
8
6.5
0.65
1.13077
5
10
8.5
0.66
1.09882
6
12
10
0.67
1.133
7
14
11.5
0.68
1.5826
8
16
13.5
0.69
1.13407
CALCULATIONS:

The mean value of R L is Calculated as follows:

RL = 1.4+1.352+1.1911+1.13077+1.09882+1.133+1.5826+1.13407
                                                        8

RL = 1.2kW
 
 

CIRCUIT DIAGRAM: RL A

RESULT:

The mean value of R L = 1.2kW .
 
 



EXPERIMENT #4

OBJECT:

To draw the Zener diode characteristic between Zener voltage and Zener current and calculate the load resistance (RL)

 THEORY:

ZENER DIODE:

Zener diode are also called voltage reference diode. They are named after C.A.Zener.Who analyzed the voltage break down of insulator. They are silicon diodes designed for a specific reverse breakdown voltage . Silicon is preferred to Ge because its higher temperature and current capability.

Zener breakdown occurs due to braking of covalent bond the strong electric field setup in the depletion region by reverse voltage.

OBSERVATION :

S.NO.
VS(Volts)
IZ (mA)
VZ (Volts)
RL kW
1
1
0.00
0.772
-
2
2
0.00
4.2
-
3
3
0.01
2.99
-
4
4
0.146
3.99
0.4
5
5
0.513
4.82
0.0667
6
6
0.92
5.38
0.2
7
7
4.55
5.43
0.253
8
8
6.9
5.75
0.28
9
9
9.05
6.03
0.304
10
10
11.22
6.98
0.303
11
11
11.28
6.5
0.316
12
12
11.30
6.56
0.314

 
  CIRCUIT DIAGRAM: RS A

CALCULATIONS:

The mean value of R L is Calculated as follows:

RL = 0.4+0.0667+0.2+0.253+0.28+0.304+0.303+0.316+0.314
                                                9

RL = 0.182 kW

RESULT:

The mean value of R L = 0.182 kW .
EXPERIMENT#5

OBJECT: -

To determine how four diode in a bridge arrangement can produce full-wave rectification.

PROCEDURE: -

1) All the four diodes are connected in such away that they all joint in one general direction to the right.

2) When at point A is positive D2 is forward biased while point while point B is negative and D3 is forward biased. Diodes D1 and D4 are reversed biased at this moment.

3) Current flows from point B through D3, up through RL through D2 to point A and the transformer.

4) A positive going voltage waveform is developed across RL.

 5) When point A is negative, point B is positive, Diode D2 and D3 are now reversed biased while D1 and D4 are forward biased.

6) Current now flow from point A through D1 up through RL in the same direction another positive voltage wave form in produced for this alternation of the sine across the transformer.

HOW CAPACIROR FILTER PULSATING ‘DC’ AND PRODUCE PURE ‘DC’: -

From figure, When the positive going pulse increases across RL, charges capacitor ‘C’ up to the peak voltage. As the pulse decreases the charges stored in capacitor discharge through RL in an attempt to keep the voltage constant across RL. Before the capacitor has a chance to discharge too far another positive going pulse arrive to charge it up to peak voltage. Pure DC is at the O/P but a small ripple voltage is riding at the top due to charge and the discharge of the capacitor.
 
 

CIRCUIT DIAGRAM:


 
 
 
 

Experiment # 7

Introduction and Working principal of C.R.O.

THEORY:

The basic parts of the CRO are showed in the figure. We will first consider the CRO’s simplified block diagram.

Cathode Ray tube: It displays quantity being measured

Vertical Amplifier:
It amplifies the signal wave from table to be viewed.
Horizontal Amplifier: It is fed with saw tooth voltage, which is then subjected to X-plates.
Trigger Circuit: It produces trigger pulse to start horizontal sweep.

Sweep Generator: Produces saw tooth voltage wave form used for horizontal deflection of electron beam. The cathode ray tube is the heart of the CRO. Its function is to provide usual displays of an input signal in waveform.
 
 

A Cathode ray tube has for basic parts:

  1. An electron gun to produce a stream of electrons.
  2. Focussing an accelerating element to produce a well-defined beam of electron.
  3. Horizontal and Vertical plates to control the path of electron beam.
  4. An evacuated glass envelop with a phosphorus screen, which gloves visible when the beam strikes it.
WORKING: APPLICATIONS:

Experiment No. 8
The Transistor as an Amplifie feeding an AC Signal as input and to calculate the gain of the Transistor.

Apparatus:
Power Supply, Multimeter, Circuit Board, Transistor and Resistor

Theory:
A Signal may be introduced to the input and amplified version of the same Signal may be appeared at the output.

The Transistor acts as an amplifier when it is in its partially turn on condition (i.e. 0.7V) at the base is partially turning on the Transitor.

An Amplifier biased between cut off and saturation Region. The input and output signal on Collector Emitter of Amplifier are 180 degree out of phase, that is when the input signal goes positive the output will go negative. The Voltage gain is Ratio between output Voltage/input Voltage. The capacitor "C" prevent DC Current from flowing between Transistor and input signal Generator.
 
 

CIRCUIT DIAGRAM