Concepts of Electronics I - Student Lab Manual

8/13/2019 Concepts of Electronics I - Student Lab Manual

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ContentsIntroduction 2

Equipment & Component List 3

Introduction to Digital Multimeters 4

Introduction to the Elenco XK-700 Electronic Trainer 6

Using Meters

Project 1 Voltmeters 12

Project 2 Ammeters 14

Project 3 Ohmmeters 16

Ohms Law

Project 4 Relationship of I and V with a Constant R 18

Project 5 Relationship of I and R with a Constant V 20

Project 6 Relationship of Power to V with a Constant R 22

Project 7 Relationship of Power to I with a Constant R 24

Resistors

Project 8 Resistor Color Codes 25

Series Circuits

Project 9 Resistance in Series Circuits 27

Project 10 Current Flow in Series Circuits 28

Project 11 Voltage in Series Circuits 29

Project 12 Power in a Series Circuit 31

Project 13 Detecting an Open in a Series Circuit 33

Project 14 Detecting a Short in a Series Circuit 35

Parallel Circuits

Project 15 Resistance in Parallel Circuits 36

Project 16 Current Flow in Parallel Circuits 38

Project 17 Voltage in Parallel Circuits 40

Project 18 Power in a Parallel Circuit 42

Project 19 Detecting an Open in a Parallel Circuit 44

Project 20 Detecting a Short in a Parallel Circuit 46

Combination Circuits

Project 21 Resistance in Series-Parallel Circuits 48

Project 22 Current in Series-Parallel Circuits 50

Project 23 Voltage in Series-Parallel Circuits 52

Project 24 Power in a Series-Parallel Circuit 54

Project 25 Detecting an Open in a Series-Parallel Circuit 56Project 26 Detecting a Short in a Series-Parallel Circuit 58

Circuit Troubleshooting

Circuit Troubleshooting Strategies 60

Breadboard Circuits 66

Troubleshooting Exercises 68

Formulas 77

Instructor Sign-off Sheet 80

October 20


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Equipment

Elenco XK-700 electrical trainer

Multi-range digital multi-meter (DMM)

Breadboard jumper wires

Testing jig (Used for troubleshooting exercises)

AA battery holder with leads

AA battery

Components

Resistors

o 1 k, carbon film, 1 watt, 5% tolerance

o 3.3 k, carbon film, 1 watt, 5% tolerance



o 10 k, carbon film, 1 watt, 5% tolerance (4)


o 47 k, carbon film, 1 watt, 5% tolerance (2)



o

11

, carbon film, 1/2 watt, 5% toleranceo 2 k, carbon film, 1/2 watt, 5% tolerance

o 300 k, carbon film, 1/2 watt, 5% tolerance

o 10 M, carbon film, 1/2 watt, 5% tolerance

o 150 , carbon film, 1/4 watt, 5% tolerance

o 5.6 k, carbon film, 1/4 watt, 5% tolerance

o 1.2 k, carbon film, 1/8 watt, 5% tolerance

o 39 k, carbon film, 1/4 watt, 5% tolerance

o 270 k, metal oxide, 2 watt, 5% tolerance

o 2.2 k, carbon composition, 1/2 watt, 5% tolerance

o 750 k, carbon composition, 1/2 watt, 5% tolerance


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DC Voltage FunctionRanges from 200mV

to 1000V DC

AC Voltage Function

Ranges from 200mV

to 700V AC

Transistor Test Function

Resistance Function

Ranges from 200to

200M

V, jackUse this jack for the red

test lead when measuring

voltage or resistance.

COM jackUse this jack for the

black test lead.

mA jack

Use this jack for the red

test lead when measuring

current from 0 to 200mA.

A jack

Use this jack for the red testlead when measuring current

from 200mA to 20A

Capacitance FunctionRanges from 2nF to

200F

AC Current FunctionRanges from 2mA to

20A.

DC Current FunctionRanges from 2mA to

20A.

Continuity / Diode Test

Function

ON / OFF power switch

Digital Multimeters

Figure P-1

Multimeters are very useful test instruments. By operating a multi-position switch on the meter they canbe quickly and easily set to be used as a voltmeter, an ammeteror an ohmmeter. Some meters havadditional features used to measure capacitance and frequency as well. They have several settingscalled ranges for each type of meter and the choice of either alternating or direct currentmeasurements.

VoltmeterTo test for voltage, first determine whether the application you're testing uses AC or DC voltage. Thenset the dial to the appropriate function and plug the red test lead into the correct jack used to measurevoltage.

Like all test procedures, when testing voltage, set the meter to the range just higher than the expected

voltage and decrement it down as needed to increase the accuracy of the reading. If you don't knowthe expected range, set the range to the highest one available. Take the black test lead and place it othe negative polarity point of the circuit you want to measure. The red test lead will go on the morepositive polarity point. When measuring voltage, the test leads of the meter must always be connectein parallelor across the component or circuit to be measured as in Figure P-2 on the next page.


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6.00

A mA COM

VPower

Supply6V

Voltmeter leads connected in parallel

with resistor being measured.

Figure P-2

AmmeterTo measure current, break the circuit where you want to take the reading. Set the meter to AC or DCcurrent depending on the source being tested. Plug the test lead into the correct jack to measure theexpected current.Note:Most meters have a separate jack that needs to be used to measure current from 0 to 200mAand from 200mA to 10A or sometimes 20A.

Insert the meter in seriesor in line with the circuit to be measured by placing the red test lead on thepositive polarity point and the black lead on the negative polarity point (see Figure P-3). Similar to thevoltage, the correct current range needs to be selected. Start by selecting the next range higher than

the expected reading. If the meter ever reads 0 when an actual reading should be present, check thfuse for the 200mA port.

12.00

A mA COM

mAPower

Supply12V

Ammeter leads connected in series

with the circuit being measured.

Figure P-3

1000

A mA COM

Remove power from the circuit prior

to taking resistance measurement.

Figure P-4

OhmmeterTo test for resistance, first remove the power from the circuit component to be tested. This preventsthe meter from becoming damaged by the source. After ensuring that all power is off, set the dial to thresistance function. Select the appropriate range on the dial. Remove the component to be measuredfrom the circuit (This prevents false readings from any other components in the circuit). Make sure thetest leads are plugged into the correct jack to measure resistance. Connect your test leads to thecomponent and take the reading.

It's important that you have good contact between the test leads and the component being tested. Dirt,oil and poor test lead connection can undesirably alter resistance readings.


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The Elenco XK-700 Electronic Trainer

This guide will explain the basic operations and features of the Elenco electronic trainer that you will beusing for the majority of the lab experiments in this course. Please take a few minutes to read throughthis guide and study the illustrations so you will become familiar with the different functions of thistrainer.

In this user guide you will identify the five main sections of the trainer. You will also learn the purposeand the function of each section.

The five sections of this trainer are listed below. See Figure P-5 for a pictorial diagram of the trainer.

1. Power supply section2. Variable resistance section3. Function generator4. Digital section4. Digital section5. Breadboard section5. Breadboard section

FigureP-5

Variable Resistance

Section

Function / Signal

Generator

Digital

Section

Breadboard SectionPower SupplySection


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Power Supply

The Elenco trainer has several built in DC power supplies to satisfy most electronic design needs.

The two variable DC power supplies produce up to +20 volts and -20 volts at 500 milliamps. Below 15the available current is over 1 amp.

Three fixed power supplies produce +12vdc, -12vdc, or +5vdc at 1 amp each.

All of the power supplies are regulated to within 150 millivolts. In other words, if you increase thecurrent draw from no load to 500 milliamps, the voltage will change less than 150 millivolts.

Figure 1

Figure 1

Variable negative voltage

control Varies negative

voltage from 0 to -20v atindicated out ut terminal.

Variable positive voltage

control Varies positivevoltage from 0 to 20v at

indicated output terminal.

Power output terminals

This provides 30VAC center

tapped at 15VAC. This also

provides the output terminalfor positive and negative

variable voltages.

On Off switch

Allows power to be applied

to all outputs. Switch will

light when on.

Ground

-12VDC fixed

volta e

+12VDC fixed

volta e

+5VDC fixed

volta e

Fuse holder

1.25A 250V

A variety of different voltages areavailable at the power output terminals.Because the Elenco trainer uses both the+20v and -20v adjustable voltagecontrols, a combined voltage of up to40vdc is possible. (See Figure P-7)

0 to +20vdcGround

0 to 40vdc

0 to -20vdc

0 to +20vdc0 to -20vd

DC Voltmeter

DC Voltmeter DC Voltmeter

Figure P-6

Figure P-7


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The power supply sections output terminal blockalso allows for the stepped down AC voltage to beused direct from the center tapped transformer.The transformer provides a voltage of 30VACfrom line to line or 15VAC from either line to thecenter tapped ground (See Figure P-8).

WARNING:Do not short the 15 VAC output to ground!

Variable resistance section

The Elenco trainer has two built in variable resistors or potentiometers that are available to use forcertain lab experiments. The values of the variable resistors are 1k ohm and 100k ohm max. Taking aresistance measurement from one side of the terminal block to the other will give the full value of theresistor (1k ohm or 100k ohm) regardless of the position of the knob. If you take a measurement fromeither end of the terminal block to the middle wiper connection, you will get a variable value that willchange with respect to the position of the knob. (See Figure P-10)

1k otentiometer

0 to 1k ohm

Full 1k ohm

Ohmmeter

Ohmmeter

30VAC

15VAC

Step Down

Transformer

120VAC

AC Voltme

AC Voltmeter

Figure P-8

Figure P-9

100k ohm potentiometer1k ohm potentiometer

1k terminal block 100k terminal block

Figure P-10


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Function / Signal Generator

The included function generator is capable of producing sine, square and triangle waveforms. Thefrequency of this generator is variable from one hertz to over 100,000 hertz in the following five ranges10-Hz, 100-Hz, 1-kHz, 10-kHz and 100-kHz. A fine adjustment control makes for easy selection of anfrequency between these ranges. The output voltage amplitude is variable between 0 and 15-VP-P.The output of the function generator may be taken from the terminal marked FREQ with respect to aground terminal in the power supply section.

Digital Section

The digital section of the trainer consists of two no bounce logic switches, 8 LED indicator lamps, 8data switches and a clock generator. The clock generator output is a 5V pulsating square wave. Thefrequency of the pulsations can be adjusted with the frequency range selector and fine frequencycontrol in the function generator section.

Waveform SelectionUse to select square,triangle or sine

waveforms.

Frequency Range Selector

Selects 5 frequency ranges

from 10 to 100,000 hertz.

Amplitude Control

Controls the voltage

amplitude of the

waveform. 0 15VP-P

DC Offset Control

Controls the DC level of the

generator output. DC may be

varied + 10V from zero level.

Fine Frequency Control

Allows easy selection of

desired function generator

frequency.

Signal Output Terminal

Terminal providesconnection point for

output signal (with

respect to ground).

Figure P-11

Figure P-12

Clock Generator Output TerminalProvides connection point for

pulsating clock signal (5VP-P).

Input Terminal for LED IndicatorsA input terminal corresponds with

A LED etc.

Logic Switches

No bounceswitches

Data SwitchesSupplies output

of 5V or 0V

depending onposition.

Data Switch Output Terminals

Output terminals for corresponding switches

Logic Switch Output Terminals

Output terminals for corresponding switches


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Breadboard Section

1

q 1660 tie points including 6es.

The Elenco trainer is eindependent bus lin

uipped with two breadboards containing a total of

Figure P-13

The board is made of plastic with a matrix of holes. Wires and component leads can be pushed intothe holes to make appropriate connections. Each hole on the board contains a metal spring contact.

When a wire or component lead is pushed down into the hole an electrical connection is made with thaholes spring contact.

The breadboards provide an interconnection bet n holes on the board using metallic bus

Figure P-14

t-in interconnections and the typical circuit board layout, some of the following

chniques are commonly used when working with a breadboard.

A jumper wire can be used to connect the positive source lead to one of the horizontal busslines marked with a plus (+) sign.

Another jumper wire can be used to connect the GND to one of the

ontal source connection row to theappropriate point(s) in the circuit on the vertical bus line portion of the board.

t into another vertical column hole in a separate bus line.Connect the component, spaced as necessary for the size of the component.

ween certaiconnections made underneath the surface. The holes are internally connected so that each 50 holehorizontal bus line is independent from the other and each small 5 hole vertical bus line is alsoconnected independently. Figure P-14 shows the internal connections of the holes on the breadboard

Vertical bus line

Horizontal bus line

Because of the buil

te

negative source lead orhorizontal buss lines marked with a minus (-) symbol.

A short jumper wire can then be used to connect each horiz

When connecting component leads, plug one lead of a component into a vertical column holeand the other lead of the componen


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1

Fig s arjust a s tions for connecting circuits usingbre b

ure P-15 & P-16 are sample series and parallel circuit connections using a breadboard. Thesemall sample of the many different methods and combina

ad oards. These examples are shown using the positive variable voltage supply.

Sample parallel circuit layout

(a) Pictorial Diagram

(b) Schematic Diagram

(a)

GroundVariable

0 to +20vdcVariable

0 to -20vdc

470 680560VA

R2 R3+

b

R1

Sample ser cuit layout

t

ies cir

orial D(a) Pic iagram

b Schematic Dia ram

b

470

680

560

VA_

R2

R3

R1

+

Figure P-15

(a)

GroundVariable Variable

0 to -20vdc0 to +20vdc

PowerFigure P-16


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1

Project Objectives:

To learn how to safely and effectively measure DC voltage using a digital multi-meter.

Gain practice in creating simple circuits from pictorial diagrams.

Learn to adjust a variable DC source for a desired output voltage.

Items Needed:Electronics Trainer Digital multi-meterJumper Wires 1.5V dry cell battery

By completin of the key proc ure d to make safe and accuratemeasuremen will also introduce important points of meter care. Be sure toremember and use these key points whenever you use a meter.

1. Make sure the meter is set on thecorrect function(ac or dc volts, amperes, or ohms).When using a non-autoranging meter, make sure the range is set high enoughfor what youare measuring. If you are not sure, start with the highest range and work down until the readin

is the most accurate.3. When measuring voltage, make sure the meter isconnected in parallelwith what you are

measuring.4. Be sure to observe polaritywhen measuring dc voltage.5. Make sure to remove powerwhen making changes to a circuit and connecting test leads.

Using MetersVoltmeters

g this project you will learn some ed s usets with a voltmeter. We

2.

Experiment 1

Voltmeter

re the

. What voltage range will give the most accurate result for this measurement?

(b) 2V (c) 20V (d) 200V (e) 1000V

0.00

Dry Cell

1. Following the safety guidelines listed above, use a digital multi-meter (DMM) and measu

voltage of a dry cell battery.

Cell voltage measures__________________________V.

2. What mode / function was the meter switched to make this measurement?

(a) A (b) V (c) V (d) DC AC DC (e) AAC

3

(a) 200mV

A mA COM

V


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1

4. What cell terminal was the red lead connected to?

5. The negative terminal of the cell should be connected to the _______ test lead

(a) black (b) red

xperiment 2

(a) negative (b) positive

__________

E

1. Connect the voltmeter across the positive output of the variable voltage power supply on your

that respective order. Have the instructor check your settings each time. (Hint) Yocombine the positive and negative variable voltages on the Elenco trainer to reach

0v.

orrect. Instructor initial:_________________

15v setting correct. Instructor initial:_________________

30v setting correct. Instructor initial:_________________

. What mode / function was the meter switched to make this measurement?

(a) ADC (b) VAC (c) VDC (d)

. What voltage range was the meter set to for the 5v and the 15v measurements?

(a) 2 (c) 20V (d) 200V (e) 1000V

. What voltage range was the meter set to for the 30v measurement?

(a) 200mV (b) 2V (c) 20V (d) 200V (e) 1000V

. The red lead was te he ___________terminal of the power supply?

(a) positive (b) negative

Voltmeter

Elenco electronics trainer. Carefully adjust the power supply to 5v, 15v, and 30v outputsettings, inwill need to3

5v setting c

2

(e) AAC

3

00mV (b) 2V

4

5 connec d to t _____

0.00

A mA COM

V

Variable VariableGround

Variable voltage

output terminal

0 to +2 0 to dc0vdc -20v


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1

UsAmm

rojec ulti-meter.

simp ms.

le DC

ems Needed:k resistor

t e currentme

1. er from the circuit g meters.ries.

4. e mode nfor what you are measuring (dc current mode).

6. erly, turn power on and take reading.

ing Meterseters

P t Objectives:o learn how to safely and effectively measure DC current using a digital mT

Gain practice in creating le circuits from schematic and pictorial diagra

earn to adjust a variab source for a desired output current.L

It- Electronics Trainer - Digital multi-meter - 1- Jumper Wires - 1.5V dry cell battery

In his project please use the following safety precautions when connecting meters to makasurements.

emove pow prior to making changes and connectinR2. Break the circuit in an appropriate place and connect the meter in se3. Observe polarity when measuring dc current.

Use the corr ct meter / functio

5. Be sure to set the range high enough for what you are measuring.If unsure, start at thehighest range and work down until an accurate reading is given.After meter is connected prop

Experiment 1

Ammeter

What mode or function should the meter be set to?

s ad short will occur and the

ircuit look like the diagrams above? Check: (Yes____, No____)

4. Connect the 1.5V cell to the circuit and read the

Current measured is:______________ mA

1. Set up the DMM to measure current from 0 to 2mA.

(a) ADC (b) VAC (c) VDC (d) (e) AAC

2. Connect the circuit shown above. (The resistor color bands will be: brown, black, red, gold)

3. Break the circuit at point A and insert the meter. Make sure the meter is in series and there iresistance in the circuit. If there is no resistance in the circuit a demeter could get damaged or destroyed.

Does your c

ammeter.

0.00

A mA COM

mA

1k

B eratt y

Point A

Schematic Diagram

1k

Dia

1.5v Dry Cell

gramPictorial


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Experiment 2

1

2.ate bus lines so the circuit will not be shorted.

3.

to the black test lead on the DMM.

5. it to the open lead of the resistor. Your circulook like the illustration above.

6. et the voltage control on the power supply to the zero output setting. Turn the power on andlowly increase the output until you measure 10mA through the circuit. Have the instructorheck your setting.

tor initial: ______________

. the voltage applied to the circ t when the power supply is adjusted so that there is acurrent flow of 5mA?

Please review the voltage safety rules!

Ammeter

1. Disconnect the previous circuit. Set up the meter to read current in the range from 0 to 20mA.

With the power OFF, insert the 1kresistor into the breadboard section of the Elenco trainer.Make sure the resistor leads are in separ

Connect a jumper from the positive variable power supply terminal to one side of the resistor.

4. Connect another jumper from the middle ground terminal

Take the red test lead from the DMM and connectshould now

Ssc

Instruc

What is7 ui

Voltage measures_____________V. Current measures_____________mA.

0.00

A mA COM

mA

+

1k

Variable Variable

0 to +20 0 to -20vdcvdc

Variable

voltage

output

terminal


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1

Us rsOhmProject Objectives:

To develop an understanding of the ohmmeter function of a DMM.

To learn how to use the variable resistance section of the Elenco trainer.

ems Needed:- Electronics Trainer - Digital multi-meter - 10k resistor- Jumper Wires - 1k resistor - 47k resistor

this project please use the following safety precautions when connecting meters to make resistanceeasurements.

1. Disconnect the circuit from the power source.2. Isolate the componentbeing measured from the rest of the circuit.3. Use the correct meter mode / functionfor what you are measuring. (ohms)4. Be sure to use the appropriate rangefor the expected resistance.5. When finished making measurements, be sure to turn the meter OFF.

xperiment 1

ing Metemeters

It

Inm

E

1. Using the resistance function of a DMM, measure and recor10,000), and a 47K(47,000) resistor.

d the resistan

The 1k(brown, black, red) resistor measures____________________.

_______________.

__________.

tors exactly measure to their specified value?__ ____ __d e.

________________________________________________________________

_________________

__________________

________________________________________________________________

4. Which ohmmeter range should have been used to measure the three resistors?

__

ce value of a 1k(1000), 10k(

The 10k(brown, black, orange) resistor measures_____

The 47k(yellow, violet, orange) resistor measures__________

2. Did the three resis _ ____________3. List some reasons why there may be ifferences from the measured and the specified valu

________________________________________________________________

_______________________________________________

______________________________________________

Range used for 1k=____________________

Range used for 10k=______________________

Range used for 47k=______________________


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1

x rE pe iment 2

Ohmmeter

1. Insert jumper wires into the two outside terminals for the 1k 100kpotentiometers(variab ce measurements?

ake s

kpotentiometer mea ______________ ge used:______________

100kpotentiometer measures:_____________ . Meter range used:_____________

mmeter is connected in this manner, what happens when you attempt to adjust the

resistance by turning the potentiometers knob?_______________________________

Why?____________________________________________________________

________________________________________________________________

__________________________________________________

3. Now mo mper wires from the outside terminal to the middle wiper terminal. Yo

should now e resistanc b e potentiometers knob.4. Set the 1k . Have the instructor check your measurement.

Meter range used:________________ Instructor initial:_______________

_____

andle resistors) on your Elenco trainer. What are the resistan

M ure the power supply is not connected!

1 sures: . Meter ran

2. When the oh

______________

ve one of the ju

be able to adjust thpotentiometer to 350

e y turning th

5. Set the 100kpotentiometer to 18k. Have the instructor check your measurement.

Instructor initial:__________Meter range used:________________

0.00

A mA COM

Variableresistor

terminal


19/81

Ohelation ip of I an tant R

ro To prove the direct relationship of current to voltage when a set resistance is given.

To obta

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - 10k resistor (brown, black, orange)

hile completing this project, keep in mind that Ohms Law states (E = I x R)

Be sure to disconnect powerwhen connecting meters and making changes to the circuit!

When measuring current, make sure a resistance is always in the circuitto avoidshorting the circuit and damaging the meter.

xperiment

ms LawR sh d V with a ConsP ject Objectives:

in more practice connecting circuits and using a DMM to make measurements.

It

W

E

1

1. Select the c range to measure dc

currentfrom

orrect meter function and

0 to 2mA.

Ma ble voltageoff the power and disconnect the meter from the

Using Ohms Law, calculate the expected voltage of thiscircuit.

2. Using the positive variable voltage as the source V, connectthe circuit shown in figures 4-1 and 4-2.Make sure the meter is in series with the circuit.

3.

5.

Calculated voltage =_________________________ V.6. Select the correct meter function and range to measure dc

voltagefrom 0 to 20 volts.7. Connect the circuit and the meter to take a voltage reading

across the 10kresistor. Remember, the meter must be inparallelwhen measuring voltage. See figure 4-3 for a schemMake sure the variable voltage control knob has not been chset and apply power to the circuit.

.

Increase the positive variable voltage until the meter reads1mA.

king sure not to change the state of the varia4.knob, turncircuit.

atic diagram.anged from when the current was

Measured Voltage =_________________________ V

mA

1

V

Figure 4-2 Schematic Diagram

Source

V

Source V

Figure 4-3

0.00

A mA COM

+

Variable

voltage

output10k

Figure 4-1 Pictorial Diagram

mA

terminal

Variable Variable

0 to +20vdc 0 to -20vdc


20/81

1

I

L ot be perfectly accurate to the calculated

v

_ ______________________

________________________________________________________________

___ ________________

8. is time setting the current at 1.5mA. What is the calculated

V.

9.

10

11.

s the measured voltage close to the calculated value in step 5?____________________

ist some reasons why the measured voltage might n

________________________________________alue. ___________________

_________________________________________

___________________________________________ __

Repeat steps 1 through 7, thvoltageof this circuit?

Calculated voltage =_________________________

What is the measured voltage?

Measured Voltage =_________________________ V.

. Increasing the voltage of the circuit caused the current to________________________

(a) increase (b) decrease

As this lab experiment clearly proved, electric current is__________________________

related to the voltage applied in the circuit.

(a) directly (b) inversely


21/81

2

hms Lawelationship of I and R with a Constant V

roject Objectives: To prove the inverse relationship of current to resistance when a set voltage is given.

To obtain practice in connecting circuits and using a DMM to make measurements.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors 10k, 3.3k

Be sure to disconnect powerwhen connectingthe circuit!

When measuring current, make sure a resistance is alshorting the circuit and damaging the meter.

ORP

It

, 1k

meters and making component changes to

ways in the circuitto avoid

Experiment

1. l

2.

3.

4.

Voltage measures =____________________ V

5. Use Ohms Law and calculate the resistance (R) from the measured values of voltage (V) andcurrent (I).

Calculated Resistance =____________________

6. What would the current of the circuit be if the 10kresistor were replaced with a 3.3k(orange

=____________________ mA

Se ect the correct meter range to measure dc current from0 2mA.

ng the positive variable voltage as the sourceUsi V,connect the circuit shown in figures 5-1 and 5-2.

the meter is in series with the circuit.

Turn on the power supply and increase the positivevariable voltage until the meter reads 1mA.

Measure the circuit voltage and be sure notto change itfor the rest of the steps in this experiment.

Make sure

orange, red, gold) resistor?

New calculated current

mA

10k

Source V

Figure 5-2 Schematic Diagram

0.00

A mA COM

+

Variable

0 to +20vd

c

Variable

0 to -20vdc

voltage

Variable

output10kterminal

mA

Figure 5-1 Pictorial Diagram


22/81

2

red, gold) resistor?

_ mA

9. new current reading. Make sure the meter range is set correctly to the calculation

10. wer supply off and remove the 3.3kresistor from the circuit. Replace it with a 1k

____________________ mA

________.

13. nclude that current is____________________ related to resistance.

7. What would the current of the circuit be if the 10kresistor were replaced with a 1k(brown,black,

New calculated current =___________________

. Turn the power supply off and remove the 10kresistor from the circuit. Replace it with a83.3kresistor.

Measure thein step 6.

Resistance now = 3.3k Current now measures:____________________ mA

urn the poTresistor.

11. Measure the new current reading. Make sure the meter range is set correctly to the calculationin step 7.

Resistance now = 1k Current now measures:

12. Keeping the circuit voltage constant at_____________________ volts and decreasing th

resistance caused the circuit current to____________(a) increase (b) decrease

From this we co

(a) directly (b) inversely


23/81

2

hms Lawelationship of Power to V with a Constant R

roject Objectives: To show the use of the power formula by demonstrating how power is related to voltage

squared for a set resistance.


ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - 10k resistor

While completing this project, keep in mind that the power formula states that (P = E x I)

Be sure to disconnect powerwhen connecting meters and making component chan

ORP

It

ges to thecircuit!

Experiment

2. e Source V to obtain 1mA of current and measurethe voltage.

______________________ mA

Voltage =______________________V

3. Using the power formula, calculate the power dissipated bythe resistor.

Calculated Power =______________________mW

4. Change the Source V to obtain 2mA of current and measure the voltage. Using the powerformula, calculate the power dissipated by the resistor.

Current now =__________________ mA Voltage now =__________________

_____mW

many times?______________

______ tim

1. Connect the circuit shown in figures 6-1 and 6-2.Adjust th

Current =

Calculated Power now =_________________

5. When we doubled the voltage the current increased by how

Therefore the product of V x I increased______ es.

mA

10k

Source V

Figure 6-2

0.00

A mA COM

+

Variablevoltage

output10kterminal

mA

Variable

0 to -20vdcVariable

0 to +20vdc Figure 6-1


24/81

2

6. er for the measured values in step 4.

__________

g

________mW

8. ____ the voltage.

9. we ow ha

11. n the

______mW

_____

Using the (P = V2/R) formula, calculate the pow

V =______________________V R =____________

P calculated =______________________mW

7. Change the Source V to 5 volts. Measure the current value and calculate the power by usinboth of the above formulas.

V now =_____________________V I now =_____________________A

P calculated using the formula (P = V x I) =______________

P calculated using the formula (P = V2/R) =______________________mW

When compared to the 20 volt condition, we now have________

(a) 1/2 (b) 1/4 (c) 1/8 (d) 1/16

When compared to the 20 volt condition, n ve____________ the power dissipation

(a) 1/4 (b) 1/8 (c) 1/16 (d) 1/32

10. Assume this circuit has an applied voltage of 8 volts. Calculate and predict what the circuitcurrent and power would be.

Predicted current =______________A Predicted power =_____________mW

Change the circuit to 8 volts. Measure the current and calculate the power based oeasurements.m

Measured current =______________A Calculated power =_______

12. Is the current with the applied 8 volts higher than when there were 5 volts applied?___

Is the calculated power higher or lower?________________

Does the change correlate with the concept of power being equal to V2/R?_____________


25/81

2

hms Lawelationship of Power to I with a Constant R

roject Objectives: To show the use of the power formula by demonstrating how power is related to current square

for a set resistance.


ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - 10k resistor

rmula states

making component

ORP

It

While completing this project, keep in mind that the power fo

Be sure to disconnect powerwhen connecting meters andcircuit!

that (P = E x I)

changes to the

Experiment

1. Connect the circu

it shown in figure 7-1.

______________

sured values ofVand Ia

VAuntil I equals 1/2 its original value.e new voltage and calculate Pusing both formulas.

V I now =_____________________A

____________________ mW

___________ mW

issipated w was double the value of current.

6. that power is proportional to I2when the resistance remainspower dissipation will increase by

(b) 2 (c (d) 4

7. er must decrease to

8. inal 14V value)

__________ mW

were applied?___________

+

2. Adjust the applied voltage (VA) to 14 volts.3. Break the circuit and insert an ammeter to measure

the current.

I =__________ mA

4. Use the mea nd calculate Pusing the power formula.

Pcalculated =_____________________mW

5. DecreaseMeasure th

Vnow =_____________________

Pcalculated using the formula (P = V x I)_

Pcalculated using the formula (I2x R)__________

Pcalculated is___________the power d hen I

(a) 1/2 (b) 1/4 (c) 1/8 (d) 1/16

We can conclude from thisunchanged. So if the current in a circuit doubles, the

______________times. (a) 1

If the current in a circuit decreases to one-third its value, the pow

) 3

______________ its value. (a) 1/3 (b) 1/4 (c) 1/6 (d) 1/9

What would happen if VAwas changed to 4.67 volts (approximately 1/3 the orig

NewVA=___________________ V V xInow =________

ICALC=____________________ A I2 x Rnow =_________________ mW

Is the power approximately one-ninth that when 14 volts

10V

Figure 7-1

A


26/81

2

RRes s

Pro

Items- Di ital- Re

nts, make sure there is no power applied to the circuit.

esistorsistor Color Code

ject Objective:To provide a hands-on experience with the resistor color code.

To determine if the resistor is operating within its specified tolerance by using an ohmmeter tomeasure its resistance.

Needed:g multi-metersistors: 2 watt- 270k

1 watt- 6.2k, 10M1/2 watt - 11, 2k, 2.2k, 300k, 750k

1/4 watt- 150, 5.6k1/8 watt - 1.2k, 39k

When making resistance measureme

Experiment

_____________ 5 =__________________________

______________ ___ =__________________________

____________ 7 =__________________________

3 =____ ______________________

________________________

sed to represent 5% tolerance =__________________________________

______

3.pe

that mith ller number by t

s the m

e end up with a percentage of the measured value to the g

1. List the 10 colors used in the resistor color code to represent the following numbers.

0 =______________

1 =_________ _ 6

2 =____ ___________

_______________________ 8 =____

4 =___________________________ 9 =__

2. List the colors used in the resistor color code to represent the following tolerance levels.

The color u

The color used to represent 10% tolerance =___________________________

How is a 20% tolerance represented? ______________________________________

Complete the table on the next page to determine if the resistors are operating within theirs cified tolerance ratings.

Example:If we have a 1kresistor with a 5% tolerance easures 965we can find if it is operating

in its tolerance rating by dividing the sma he larger number and subtractingw

from 100%. In this case the smaller number i easured value and the larger number is thgiven (color code) value.

If we take 965and divide by 1000we get .965

W iven value. To find out if theresistor is operating within its tolerance we need to subtract from 100% so we move the decimapoint two places.

100% 96.5% = 3.5%


27/81

The percent of difference between the measured value and the given color code value of the

2

4. e rmine if the resistors p ch of the

following conditions.

be sufficient if 11 volts were applied across the1.2kresistor?

________________________________________________

r tingbe sufficient if 50 mA were flowing through the 150resistor?

_ _____________________________________________

er tingbe sufficient if 350 volts were applied across the 300kresistor?

__________________________________________________________

f difference In tolerance (yes/no)

resistor is 3.5%. Therefore the 1kresistor is operating within its 5% tolerance.

Complete the table below. Use an ohmmeter to measure each resistor. Refer to the exampleabove to calculate if each resistor is operating within its tolerance rating.

Resistor measures? % o

270k- 2 watt

6.2k- 1 watt

11- 1/2 watt

2k- 1/2 watt

2.2k- 1/2 watt

300k- 1/2 watt

Use Ohms Law to d te ower rating would be sufficient in ea

Would the power rating

__________

Would the powe ra

___________ _

Would the pow

ra

750k- 1/2 watt

10M- 1/2 watt

150- 1/4 watt

5.6k- 1/4 watt

1.2k- 1/8 watt

39k- 1/8 watt


28/81

2

Serieses tance in Series Circuits

oject Objective: To verify the series circuit resistance formula by making resistance measurements under

various circuit conditions.

ms Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 3-10k, 47k, 100k, & 220k

hen making resistance measurements, make sure there is no power applied to the circuit.

CircuitsR

Pr

is

Ite

W

Experiment

1. Connect the circuit as shown in Figure 9-1.

Remember! Disconnec

t the power supply in this project!

orrectly label your answers.

___________________________.

tance of each individlues below.

_________________________.

__.

um of the individual resista ces,

___.

.

5. 7kresistor?

.

6. istance.

__.

7. ircuit increases, then the total resistance will

e tota

8. = 47k. Predict RTand then

__________________

_______________________

_______________________

10k

R12. Measure the resistance of the entire circuit using anohmmeter. Remember to c

R total =_

10

10k

R2

R

Figure 9-1

3. Measure the ual resistor, andrecord the va

resis

3

R1=_____________________________.

R2=____

R3=___________________________

4. Since the total resistance of a series circuit equals the s n

R1+ R2+ R3=__________________________

Therefore RT=_____________________________

What would the new R be if R were changed to a 4T 3

Predicted RT=_____________________________

Change R3to 47kand measure the new total res

New RT=___________________________

In conclusion, if any single resistance in a series c

___________________. If any single resistance in a series circuit decreases then thresistance will___________________.

Configure the circuit so that R1= 220k, R2= 100k, and R3measure RTto verify.

PredictedRT=_____________________ Measured RT=___

Does the measured value equal the predicted value?_____

What could cause a difference?___________________


29/81

2

Curr

Projecis the

tems- El- Ju

Make s

Series Circuitsent Flow in Series Circuits

t Objective: To verify that the current in a series circuit same no-matter where the measurement is

taken in the circuit.

I Needed:ctronics Trainer - Digital multi-meteremper Wires - Resistors: 1k, 4.7k, 3.3k, & 10k

ure power supply is off when connecting meters or changing circuit components.

Experiment

1. Connect the initial circuit as shown in Figure 10-1.

the circuit and measure the current.

. Swap positions of R1and the ammeter and record thet reading.

ing is now__________

se, the current reading was_________________.

taken in a series circuit. The current readin

____________path for current to flow

5. he meter to different points in the circuit and record the

t reading was_________________.

re affecting the current flow through all part

sing it, would it change the IT?__________

___

6. e circuit and record the

me amount in every point in the circuit. This is because the current

rrent.

b.) alternating c.) the same d.) direct

1kmA

2. Apply 11 volts to

3.3

R1

R2

3

Current =_________________. +

VA3_new curren

RCurrent read _______.

4. Swap positions of the ammeter with each of theremaining resistors and record the current readings.

4.7kFigure 10-1

In every ca

It doesnt matter where the current measurement is

remains the same. This indicates that there is only__

Change R3to a 10kresistor. Move tcurrent readings.

In all cases, the curren

By increasing the resistance in a series circuit we a

of the circuit. If we were to change RTby decrea

Would ITincrease or decrease?______________

Now change V to 30 volts. Move the meter to different points in thAcurrent readings.

In all cases, the current reading was_________________.

Increasing the VAin a series circuit caused ITto change through all parts of the circuit. It

changed by the sa

throughout the entire series circuit is_________________ cu

a.) different


30/81

2

erVoltage in Series Circuits

Projec

Items- El- Ju - Resi , 18

ake sure power supply is off when connecting meters or changing circuit components.

S ies Circuits

t Objective:To use measurements and calculations to demonstrate the proportional relationship ofresistance and voltage in a series circuit.

Needed:ctronics Trainer - Digital multi-meteremper Wires stors: 1k, 4.7k k

M

Experiment

.1. Connect the initial circuit as shown in Figure 11-1

2. Apply 12.5 volts to the circuit and fill in the following table.

VA=

V1=

V2=

V3=

I =T

3. Since the current is the same through all the resistors, the

p across each resistor is directly related to its__________________________

.

Ki fs he sum of voltage drops around a closed loop circuit must

equal the applied voltage (VA). Does it?__________________.

5. Calculate the percentage of the applied voltage that is dropped by each of the resistors. Use

the following example for V1 then solve for V2&V3. Percentage = x 100

V1 ________ % of VA

2 A 3 _________ % of V

6. Predict what value V would be if V were increased to 22 volts.

________

voltage dro

4. Add the individual voltage drops and record the sum

V1+V2+V3=__________________________.rchhof Voltage Law states that t

=_____________

V =_____________________ % of V V =___________

3 A

V3 Predicted =____________________.

Change VAto 22 volts and measure V3.

V3Measured =____________________.

7. V3is now what percentage of VA?_____________________ %

Is this the same percentage as when the applied voltage = 12.5 volts?________

1k

4.7

18k

1

2

R3

Figure 11-1

R

+

RVA_

V1

VA


31/81

3

the voltage drop percentages of VA. If one of

_____________ voltage,

________ voltage.

8. g the voltage divider formula.

x x VT)

V calculated =_________________. V calculated =_________________

9. Measure V1and V2with 22 V applied to the circuit.

Changing the applied voltage does not change

the Rs were changed, would the distribution percentages change?__________________

In conclusion, in a series circuit, the largest Rwill drop the_____

and the smallest Rwill drop the__________

Assuming VT= 22 volts, calculate V1and V2usin

(V =Rx

RT

1 2 .

V1measured =_________________. V2measured =_________________.

Do the measured values of V1and V2validate the calculations using the voltage-divider

formula?_________________


32/81

3

eries Circuitsower in a Series Circuit

roject Objective: To demonstrate that power distribution in a series circuit is directly related to the distribution of

resistance.

To verify that the total power equals the sum of all the individual power dissipations.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 1k, 4.7k& 10k

ake s re power supply is off when connecting meters or changing circuit components.

SP

P

It

M u

Experiment

Figure 12-1.1. Connect the initial circuit as shown in

2. Apply 20 volts A) to the circuit. Measure each of the individuald the current, and then calculate the power

_____________________

______________

ted =_________________________

wer dissipated by each resistor is

irect _________________________.

power rating c.) composition d.) resistance

ipate the ________ p er.

.

____________________ we)

3. e ord the su ions.

___

(Vvoltage drops an

dissipated by each resistor.

V1=_________________________

V2=____

___V3=_____ ___

IT=_________________________

P1calcula

P2calculated =_________________________

mA

VA

1kR1

+

4.7

10k

Figure 12-1

R2

R3

P3calculated =_________________________

Since the current is the same through all the resistors, the po

d ly related to its

.) b.) physical sizea

____________ owThe resistor with the largest value Rwill diss

a ) most b.) least

The resistor with the smallest value Rwill dissipate the po r.a. most b.) least

R c m of all the individual resistor power dissipat

P1+P2+P3 =____________________.

Calculate the total power by using the formula: PT= VTx IT

PT= VTx IT=__ _______________.


33/81


34/81

3

SeriesDetecting an Open in a Series Circuit

Projec en an open develops in a series circuit.

o prove that the applied voltage appears across the open portion of a series circuit.

ems eeded:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 1k, 4.7k& 10k


Circuits

t Objective:o provide experience with the change that occurs wh

T

T

It N

M

Experiment

1. Connect the initial circuit as shown in Figure 13-1.

and2. Adjust the VAto 15 volts. Measure and record the currentindividual voltage drops.

I =_________T _________________

V1=_________________________

V2=_________________________

_________________

2

een R1and R3. Measure and recordal voltage drops.

w in a series circuit, creating an open within the

___________.

.) continuity b.) discontinuity

__________

b.) low

______ volts because, with zero current, the

crease, decrease)_____________________

(increase, decrease)____________________

V3=_____ ___

. Simulate an open circuit by removing R and leave the circuit3open betw

and individu

the current

IT=__________________________V1=_________________________

V2(across open)=_________________

V3=_________________________

Since there is only one path for current to flo

series circuit will cause______________

a

The total resistance of the circuit then appears to be infinitely____________

a.) high

The voltage drop across R1and R3were___

I xRmust equal_________.

If any part of a series circuit opens, RTwill (in

to_____________________and ITwill

mA

VA

1k

4.7k

10k

R1

+

R2

R3

Figure 13-1


35/81

3

________________and the

e ope resis ____________________to

4. oved from the circuit instead of R2.

______

5.

______

____________________

to_____________________. The voltage drops across the unopened resistors will

(increase, decrease)_____________________to_____

voltage across th n tor will (increase, decrease)_

_____________________.

Predict the results if R3were to be rem

IT=__________________________

V1=___________________

V2=_________________________

V3=_________________________

Replace R2and remove R3as suggested in step 4. Make the following measurements andrecord the results below.

IT=__________________________

V1=___________________V2=_________________________

V3(across open)=_________________

Do these results verify the results of step 3?


36/81


37/81

3

ParallelRes

Projec t the total resistance in a parallel circuit is less than the least

Items- El- Jumper Wires - Resistors: 18k, 100k

wer applied to the circuit.

Circuitsistance in Parallel Circuits

t Objective:To verify tha value resistance inparallel.

To provide practice using parallel resistance formulas and confirming them through circuit

nts.measureme

Needed:ectronics Trainer - Digital multi-meter

, 220k& 3 - 10k

When making resistance measurements, make sure there is no po

Experiment


2. Measure R at points A and B.

equal resistors are connected in parallel,

the total resistance is equal to________________________the resistance of one branc

4. After calculatingR , use an ohmmeter and measure at points A and B with a second 10kD.

______.

rted between points E and F. Use the

RTcalculated =_______________________.

, the total resistance of the circuit is equal

of one branch.

6.

T

RT=_______________________.

3. Calculate RTif a 10kresistor were to be insertedbetween points C and D. Use the product over sumformula.

RTcalculated =_______________________.

When two

T

resistor inserted at points C and

RTmeasured =_________________

5. Calculate RTif a third 10kresistor were to be insereciprocal formula.

When three equal resistors are connected in parallel

to________________________the resistance

After calculatingRT, use the ohmmeter and measure at points A and B with a third 10kresistor inserted at points E and F.

RTmeasured =_______________________.

10k

R1R2

A

B

C E

D F

Figure 15-1

1

R1

1

R2

1

R3

1+ +

=RT

RT=R1xR2

R1+R2


38/81

3

7. if R2were changed to 100kand R3werehanged to 18k.

TCalculated =_______________________.

rocal, Calculated =_______________________.

8. Change the circuit a sc e circuit at

sistive branch in parallel.

9. total resistance using either formula then

____________________.

_________

of the parallel circuit will b )__________________than the leas

value resistive branch in parallel.

Using both parallel resistance formulas calculateRTc

Product over sum, R

Recip RT

s de ribed in step 7 and measure the total resistance of thpoints A and B.

RTmeasured =_______________________.

In conclusion, the total resistance in a parallel circuit is less than the (highest, lowest)

__________________value re

Now replace R3with a 220kresistor. Calculate themeasure RTat points A and B.

RTcalculated =___

RTmeasured =_______________________.

Does this result confirm the conclusion in step 8? __________No matter how large the value of resistive branch that is added to a parallel circuit, the total

resistance e (higher, lower


39/81

3

arallel Circuitsurrent Flow in Parallel Circuits

roject Objective: To verify that the amount of current through parallel branches is inverse to the branchs

resistance value.

To confirm Kirchhoffs Current Law by verifying that the total current in a parallel circuit equals

the sum of the individual branch currents.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 10k, 18k, 47k, 100k


PC

P

It

M

Experiment

et1. Connect the circuit as shown in Figure 16-1 and sthe applied voltage to 10 volts.

2. Find the total circuit current and the current flowing

X in Figure 16-1 and measuring

in series when taking current

1 _________________ 3 __________.

I = . IT= .

ce value in R2is roughly____________________times larger than the

ly____________________the current

___________________times

R3 roughly ____ _______

an conclude from this experiment that the current through paralle

nches______________. We can also observe

d currents that the total circuit current is ________________

3. a 100

nts one at a

3 __.

T

1 3 2

through each parallel branch by breaking the circuitat the appropriatewith an ammeter.

Remember, the ammeter leads must beconnectedmeasurements!

I =______ ___. I =_______________

__________________________ _________________________2

The resistan

resistance in R1. The current through R2is rough

through R1. The resistance value in R3is roughly_

larger than the resistance in R1. The current through

the current through R1. We c

is ___ _ ___

branches is inversely proportional to the bra

from the measure equal to the

of the individual branch currents.

Remove R2from the circuit and replace it with kresistor. Leave the applied voltage at0 volts and measure and record the circuit curre time.1

I1=__________________________. I =_______________________

=__________________________. I =_________________________.I2

id the current through R orR change when R was increased to 100k?____________D

Figure 16-1

+

_ 10k 47k18kVA

R1 R2 R3


40/81

3

h _____________Did the total current c ange? If so, was the change in ITthe same as the

change in I2?_____________ This proves that ITis the sum of all the______________

currents. Since R1is 1/10 the value of R2, I1should be_______________times the value

of I2. Is it?_______________


41/81

4

arallel Circuitsoltage in Parallel Circuits

roject Objective: To verify that branch voltages are equal in a parallel circuit.

To verify that each branch voltage equals the applied voltage in parallel circuits.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 3 - 10k, 100k, 220k


xperiment

PV

P

It

M

E


2. Apply 12 volts to the circuit and measure and recordall of the branch voltages.

V =_______________________A

___.

V1=__________________________.

V =__________________________.2

_____________

m the above ________

________________________________________________________________

__________________________________________________

_________________________________

__ ________________________

3. Keep the applied voltage at 12 volts and measu

ge and rec d the results below.

A V2=________________________.

1 V3=________________________.

step 2?___________________________

V3=_________ ____.

What two facts can we conclude fro measurements?____________

______________

_______________________________

____________________________________

__

Change the value of R3from 10kto 100k.ll of the branch voltages and the source voltaa or

V =_________________________.

=_________________________.V

id all of the voltages measure the same as inDhis indicates that if the resistance value of a branch in a parallel circuit is changed, it will notT

affect the branch voltages. These branch voltages are not separate voltages but are in factthe same voltage.

Does the total circuit current change if one branch resistance changes?_______________

Does the current change through the unchanged resistance branches? _______________

oes the current change through the changed resistance branch?___________________D

10k

+

R1VA

10k

R2

10k

R3

Figure 17-1


42/81

4

4. it. We will labe

rcuit v

at when we add additional resistive branches to a parallel circuit, this

Add a fourth parallel branch by inserting a 220kresistor to the end of the circu

this resistor as R4. Measure and record the ci oltages with the 12 volts applied.

VA=_________________________. V3=________________________.

V1=_________________________. V4=________________________.

V2=_________________________.

We can conclude th

change_______________________affect the voltage across the other parallel branches


43/81


44/81

4

____

e resistor is of__________________value

each branch current and calculating the individual power dissipations and cuit powe

nged did it

____________

When the resistance did it

did it

A

branch is equal and the current is________ ___________proportional to the branch

resistance. Therefore V xIwill be greater if th

4. Remove R2and replace it with a 10kresistor. Complete the following table by measuringthe total cir

Keep the applied voltage at 12 volts.

When the resistance in one branch cha=V cause the power dissipated in that branch to change?

I = __________

in the one branch changed

1

cause the power dissipated through the unchangedresistive branches to change?

______________________

When the resistance in the one branch changedcause the total power dissipated in the circuit tochange?

______________________

I =2

3=I

=P1

=P2

P =3

PT=


45/81

4

arallel Circuitsetecting an Open in a Parallel Circuit

roject Objective: To provide experience with the change that occurs when an open develops in a parallel circuit.

To verify that the total circuit current will decrease by the same amount that was passingthrough the defective branch prior to it becoming open.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 47k, 100k, 220k


xperiment

PD

P

It

M

E


2. Apply 30 volts to the circuit. Measure the total circuit

current and the individual branch currents. Calculate RT.

IT=____________________________.

RT=___________________________.

I1=_____

_______________________.

______________

sistance is less than the______________________value resistance branch.

b.) lowest c.) both a & b

__________of the branch currents.

branch. Keep the applied voltage at

ual branch currents. Calculate RT.

I2=_________________________.

T I3=_________________________.

RTwill__________________. Therefore,

pe less _______________ pat

I =_________ _____.2

I3=____________________________.

The total re

a.) highest

The total circuit current is equal to the____________

3. Remove resistor R1to simulate an open in that particular30 volts and measure the total circuit current and the individ

IT=__________________________.

=_________________________.R

=__________________________.I1

f any branch of a parallel circuit becomes open,I

ince the voltage remained the same, ITwill__________________.s

Did the current through R2and R3change when R1became open?__________________

RTincreased because when R1became o n there was one _

The current through the open branch decreased to________________ mA.

When R1became open, what happened to the current through the unopened branches?

Figure 19-1

+

_ 47k 220k100kVA

R1 R2 R3

mA


46/81

4

e whe

4. p 2, ce to

P ____________

=_________________________

5.

1

=

arallel circuit becomes open, is the power dissipated by the other

ame open.

Did the voltage across all the branches chang n R1became open?_______________

Using the normal circuit condition values in ste alculate each branch power dissipation antal circuit power dissipation.th

=_________________________ =_____________PT 2

____________P1 P3=_____________

Calculate each branch power dissipation and the total circuit power dissipation using the values

R was open in step 3.when

=_________________________ P =_________________________PT 2

_________________________ P =_________________________P1 3

When one branch of a p

branches affected?____________________. Is PTaffected?__________________

PTwill____________________ by the same amount of power that was being dissipated

y the opened branch before it becb


47/81

4

arallel Circuitsetecting a Short in a Parallel Circuit

roject Objective:To provide experience with resistance changes that occur when a short develops in a parallelcircuit.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 47k, 100k, 220k

o not use the power supply for this project!

PD

P

It

D

xperimentE


2. Using an ohmmeter, measure between points A and Bto find the total resistance of the circuit. Remember,there is to be no power applied to the circuit when

making resistan ce measurements!

1becoming shorted by removing it and

jumper wire. Measu

____.

anch of a parallel circuit is shorted, RT(increases, decreases)_______________

wer supply, assume there is 10v applied between

ugh R2?__________________.

_____________.

ould the voltage reading be across R2?___________

circuit. Use the assumed 10v applied and

e power supply?______________4.

__________________________

__________ to

rrent through the un-shorted branch increase or decrease?_______________

RT=_________________________.

3. Simulate Rreplacing it with a re the new RTand record the result below.

New RT=_____________________

When a br

to________. Without connecting the po

points A and B. How much current would be going thro

How much current would be going through R3?_____

With the assumed 10v applied, what w

Across R3?____________.

Assume there is 0.01of resistance in the shortedcalculate the circuit current using Ohms Law.

IT=________________.

Would this be enough current to blow the fuse on thRemove the jumper wire and place R1back into the circuit. Now simulate a short in branch R2by replacing resistor R2with a jumper wire. Measure and record RTagain.

RT= .

A short in any branch of a parallel circuit will cause RTto_____________

________.

Does the cu

Figure 20-1

47k 220k100kR1 R2 R3

A

B


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4

ombination Circuitsesistance in Series-Parallel Circuits

roject Objective:To verify series and parallel resistance rules as they apply to series-parallel combination circuits.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 1k, 4 - 10k


xperiment

CR

P

It

M

E


ltage to obtain a total circuit current

______________________.

_________________

______________________.

__V and the total circuit current is

_________mA, then according to Ohms Law the total resistance must be

he result in step 1?__________________

_____________

___________________

________________

4. er from the circuit and measure the total

sist

T .

cuits, the total resistance equals the sum of all

aralle

2. Calculate the total circuit resistance from the resistorvalues given.

RT=__________________________.

3. Apply enough voof 1.2mA. Measure and record the following voltages.

VA=____

V1=_____ ____.

V2=__________________________.

V3=____

V4=__________________________.

Since the applied voltage is___________________________

___________________. Is this close to t

Which resistors in this circuit are in parallel?________

Is the voltage the same across these resistors?

Which resistors are in series and carry IT?___

Disconnect the power supplyand the ammet

ance with an ohmmeter.re

R =__________________________

conclusion, in series-parallel combination cirIn

he components in________________________plus the equivalent resistance of pt

omponents whose combined resistance is effectively in ________________________c

ith the components in the main line.w

mAR1

1kR2

R3 R4

10k

10k 10k

Figure 21-1

+

VA


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4

5.

6. d in step 5 and

= .

T

mA

VA

Calculate what the total resistance of the circuit

would be if a 10kresistor (R5) were added inparallel to R2. Use Figure 21-2 as a reference.

RT calc=__________________________.

Connect the circuit as describe

measure RT. Make sure there is no powerpplied to the circuit.a

RT meas

riefly describe the process used to calculate R for

__________________________

B

this circuit.

jumper above R3and R4and below R2and R5were to be removedWould RTchange if the

from the circuit?_____________________

+

R11k

Figure 21-2

R3 R4

10k

10k

R210k

R510k


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5

ombination Circuitsurrent in Series-Parallel Circuits

roject Objective:To better understand the characteristics of current flow in series-parallel combination circuits bycombining both the series and parallel circuit analysis methods previously learned in the course

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 1k, 3.3k, 4 - 10k, 2 - 47k, 100k


xperiment

CC

P

It

M

E


2. Connect the ammeter to read I and apply just enoughTvoltage to have a total circuit current of 600A.Measure all of the voltage drops and the current

through each com ponent. Record your results below.

____________________.

_____________

____________________.

________________________ I3=________________________.

________________________.

I5=________________________.

________________________.

I7=________________________.

ent flowing through them?________________

rtion of the circuit after it has been simplified?

ts, the current flow through a given component

d the

d in_

arallel portions of the circuit.

VA=________________________.

V1=____

_________ __V2= .

V3=________________________.

V4=____

V5= .

V6=________________________. I4=

V7=________________________.

I1=_________________________. I6=

I2=_________________________.

Which components have the total circuit curr

What is the resistance of only the parallel po

__________________________

It should be noted that in series-parallel circui

depends on where the component is locate in circuit. The series portion of the circuit

can be solved by using the same rules as use _____________________circuits, an

the parallel portion can be solved by using the rules for______________________

circuits. The circuit can then be finalized by combining the results of both the series and the

p

mAR1

1k

VA

+

Figure 22-1

R1

4

R2

R3

100k

47k

R510k

R70k

R610k

10k


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5

3. nts if

dicate below whether each current will increase, decrease orstay the same

will . I will

________________________. I6will_______________________.

. I will_______________________.

l________________________ I _______________________

will pass through the unchanged parallel branch.

4. e all of the circuit

voltage drops and curren

=_____________ ____________

=_____________ ____________

=_______________ =____________

.

______.

5. original 10kused

s and weasurements as needed to verify or correct your

_

_

_

ent

____

a

Predict what will happen to all the circuit curre R6were changed to a 47kresistor.In .

________________________ _______________________.I1 5

I2 will

will________________________I3 7

I4 wil . T will .

creasing the resistance value of any component in a series-parallel combination circuit willIn

ause the total current to________________________. This is true with not onlyc

ombination circuits but for any circuit. It is possible for component currents to increase in ac

parallel circuit because of the changed resistance value. This is due to the fact that a larger

percentage of the total current

Verify your predictions in step 3 by replacing R6with a 47kresistor. Measurts using the same applied voltage used in step 2.

V1 ___________. I1= ___________.

V2 ___________. I2= ___________.

V3 _________. I3 ___________.

V4=________________________. I4=_______________________.

V5=________________________. I5=_______________________

V6=________________________. I6=_______________________.

V7=________________________. I7=_______________________.

VA=________________________. IT=_________________

Do these measurements agree with the predictions in step 3?___________________

hange R6from the 47kto a 3.3kresistor. This resistor is less than theCin step 2. Predict which currents will increa e hich ones will decrease. Record yourpredictions below. After predicting, make mpredictions.

Which currents will increase?___________________________________________

_______________________________________________________________

Which currents will decrease?___________________________________________

_______________________________________________________________

Decreasing the resistance value of any compon in a series-parallel combination circuit will

cause the total current to______________ ______. This is true with not only

combination circuits but for any circuit. It is possible for a component current to decrease in

parallel circuit when the total circuit current is increased. This is because a smaller percentage

of the total current will pass through the unchanged parallel branch.


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5

Combination CircuitsVolt

Projec

Items- El- Ju

Make s

xpe

age in Series-Parallel Circuits

Objective:tTo better understand the characteristics of voltage distribution in a series-parallel circuit bytaking measurements and making observations.

To verify that a components voltage drop is affected by that components value and location in

a series-parallel circuit.

Needed:ctronics Trainer - Digital multi-metere

mper Wires - Resistors: 1k, 3 - 10k, 18k

ure power supply is off when connecting meters or changing circuit components.

E riment


2. Assume there is a total current of 700A. Calculate

all of the circuit voltages and record the results below .

.

.

____________.

V1=________________________

____________________

_____________

s?____________

A of total circuit current. Measure all of the

4=________________________.

2 5 ________________________.

VA=________________________.

ns in step 2? ________________________

ge drop?________________ Why or why not

__________________________________

__________________________________

___________________________

___________________________

V2=________________________.

V3=________________________.

V4=____

V =_________ __.5

What would the applied voltage need to be to obtain

these result

3. Apply the correct amount of voltage to obtain 700circuit voltages and record the results below.

V1=________________________. V

=________________________. V =V

3=________________________.V

id the measurements confirm the calculatioD

Did the largest resistor have the largest volta

______________________________

______________________________

_____________________________________

Which components does ITpass through?________

The combined resistance of the parallel section can be considered to be in series with the

mA

R2

3

10k

R518k

R410k

VA

+

R

R 10k

1

1k

Figure 23-1


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5

____

4. with a

5.

(largest branch, main line)_____________ ___________components.

Will V3increase or decrease if R5is replaced jumper wire?___________________

Make the circuit change suggested in step 4.

Did V3 change as predicted in step 4?________________________

When the resistance in a parallel branch is decreased, this causes the total circuit current to

________________________. This causes the voltage drops of the components that arin series with the main line to________________________. Because of this, a lesser

amount of applied voltage is dropped across R3.


55/81

5

ombination Circuitsower in a Series-Parallel Circuit

roject Objective: To illustrate the power distribution characteristics of a combination circuit by making

measurements and calculations.

To verify that the electrical parameters of a series-parallel circuit are influenced by the electric

location rather than the physical location of a component.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 1k, 10k, 18k, 47k


CP

P

It

M

Experiment


2. Apply the correct amount of voltage to obtain 1.2mA

rent. Calculate R andV and

A calc

ted by each compon

_____________________.

P1=_________________________

2=_________________________

__________. P3=_________________________

P4=_________________________

wer dissipated in this series-parallel circuit?

____________________

________o e circuit dissipate more or less power with a

ig

te more or less power with a

mA

of total circuit cur T Arecord your results below.

RT calc=________________________.

V =________________________.

3. Measure each individual voltage drop and calculatessipathe power di ent in the

circuit.

VA=_________________________.

V1=____V2=_________________________.

V3=_________________________. P

V4=_______________

PT=_________________________.

What two units are directly proportional to the po

1.________________________ 2.____

Is this true with any circuit?______________

D the components in the parallel portion of th

h her resistor value?______________________

o the components in the series portion of the circuit dissipaD

igher resistor value?______________________h

hich component in the circuit dissipated the most power?______________________W

VA

+

R2

47k 18k

R3 R4

R11k 10k

Figure 24-1


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5

ombination Circuitsetecting an open in a Series-Parallel Circuit

roject Objective: To demonstrate the effects of an open occurring in both the series and parallel portions of a

combination circuit.

To observe what happens to the total circuit current when an open occurs in a series-parallel

circuit.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 1k, 3 - 10k, 47k

CD

P

It

Make sure power supply is off when connecting meters or changing circuit compon

Experiment

ents.


2. Apply the correct amount of voltage to obtain

them below.

.

_____________________.

______________

_____________________.

V =_________________________ .

I3=__________________________

= . I4=__________________________

= . I5=__________________________

h ___________________This is

e ________with the main line.

h ___________________This is because

e with the main line components.

R mulate an open in the main line of the circuit.s.

mAR1

R210k

R310k

10k

1.2mA of total circuit current. Measure the circuitvoltages and record

VA=_________________________

V1=____

___V2=_____ ___.

V3=_________________________.

V4=____

5 .

3. Measure the current through each component

IT=__________________________.

I1 __________________________

I2 __________________________

W ich resistances in this circuit does ITflow through?

b cause these resistances are in___________

W at resistances have the same voltage drop?

th se resistances are in___________________

4. Remove resistor 5from the circuit. This will si

Measure and record the following circuit voltage

VA=_________________________. V3=_________________________

V1=_________________________. V4=_________________________

VA

1k

Figure 25-1

+

R5

R447k


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5

ombination Circuitsetecting a short in a Series-Parallel Circuit

roject Objective: To demonstrate the effects of a short occurring in both the series and parallel portions of a

combination circuit.

To observe what happens to the total circuit current when a short occurs in a series-parallelcircuit.

ems Needed:- Electronics Trainer - Digital multi-meter- Jumper Wires - Resistors: 1k, 3 - 10k, 47k

CD

P

It

Make sure power supply is off when connecting meters or changing circuit compon

ents.

Experiment


_____________________.

_____________

V =_________________________.

_____________________.

V4=_________________________.

V .

3.

. I3=__________________________

. I4=__________________________

. I5=__________________________

__________and____________________

, _______________and_______________

the main line components.

4. m r wire. Measure and record the new voltage

A V3=_________________________

1 4

m

Concepts of Electronics I - Student Lab Manual

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Transcript of Concepts of Electronics I - Student Lab Manual