Understanding Digital Oscilloscopes and Function Generators

School

COMSATS Institute of Information Technology, Islamabad**We aren't endorsed by this school

Course

EE 231

Subject

Electrical Engineering

Date

Dec 11, 2024

Pages

Uploaded by MateGuanacoMaster949

𝐂𝐎𝐌𝐒𝐀𝐓𝐒𝐔𝐍𝐈𝐕𝐄𝐑𝐒𝐈𝐓𝐘𝐈𝐒𝐋𝐀𝐌𝐀𝐁𝐀𝐃LAB REPORT NO.1NAMEM.IBRAHIMREGISTRATIONNOFA23-EEE-003CLASSEEEINSTRUCTORNAMEMuhammad Ali

DATE11-09-2024Introduction to Instruments. (Digital Oscilloscope and Digital Function Generator) and Software LT spice:Objective:The primary objective of this experiment was to familiarize ourselves with thefundamental principles and applications of digital oscilloscopes, digital functiongenerators, and the LT spice simulation software. By conducting experiments andanalyzing the results, we aimed to develop a solid understanding of these essentialtools in electrical engineering.Equipment: Signal GeneratorPower supplyProbs LT spice Theory:Digital Oscilloscope:A digital oscilloscope is a measurement instrument used to visualize andanalyze electrical signals.It samples the input signal at a high rate and stores the digitized data inmemory.Features include:oSampling rate:Determines the accuracy of waveform representation.oBandwidth:The maximum frequency a scope can measureaccurately.

oChannels:The number of input signals that can be measuredsimultaneously.oTriggering:Controls when the oscilloscope starts capturing data.Digital Function Generator:A digital function generator produces various types of electronic signals,such as sine, square, triangle, and sawtooth waves.It offers precise control over amplitude, frequency, and duty cycle.Commonly used for testing circuits and components.LT spice:A free, high-performance analog circuit simulator developed by LinearTechnology.It allows users to design, simulate, and analyze electronic circuits.Features include:oSchematic capture:Creating circuit diagrams using a graphicalinterface.oSimulation:Running simulations to observe circuit behavior.oWaveform analysis:Examining output waveforms and analyzingcircuit performance.Procedure:Oscilloscope Familiarization:Connect a function generator to the oscilloscope's input channel.Generate a sine wave and observe its waveform on the oscilloscope screen.Adjust the signal's amplitude, frequency, and offset and note thecorresponding changes on the oscilloscope.

Explore other waveform types (e.g., square, triangle) and measure theircharacteristics.Function Generator Exploration:Generate various waveforms (sine, square, triangle, sawtooth) and observetheir shapes on the oscilloscope.Experiment with different frequencies and amplitudes to understand theireffects on the waveforms.Investigate the duty cycle of square waves and its influence on thewaveform's shape.Task 1:Sinusoidal wave of 2 KHZ and 5Vp-p:OFFSETTo-1V:Generate a sinusoidal wave of 2 KHZ and 5Vp-p. Connect the signal usingprobes to the oscilloscopeAdjust horizontal and vertical position and scale knobs and try to understandtheir effect.Measure the voltage Vpp, Vrms, Vmax, Vmin

Waveform on Oscilloscope:OFFSETTo1.5V:CALCULATION:DC COUPLINGAC COUPLINGVpp: 5.041VVpp: 5.041VVVrms: 2.062 VVrms: 1.79 VVmax: 1.521 VVmax: 2.52VVmin: -3.519 VVmin: 2.51VBy pressing time, we get the value of frequency and period.Frequency = 2.00kHzPeriod = 500us

OFFSETTo1.5V:Generate a sinusoidal wave of 2 KHZ and 5Vp-p. Connect the signal usingprobes to the oscilloscopeAdjust horizontal and vertical position and scale knobs and try to understandtheir effect.Measure the voltage Vpp, Vrms, Vmax, VminWaveform on Oscilloscope:

CALCULATIONS:DC COUPLINGAC COUPLINGVpp: 5.041VVpp: 5.041VVVrms: 2.337VVrms: 1.79 VVmax: 4.041 VVmax: 2.52VVmin: -1.039 VVmin: -2.51VBy pressing time, we get the value of frequency and period.Frequency = 2.00kHzPeriod = 500usOFFSETTo2V:Generate a sinusoidal wave of 2 KHZ and 5Vp-p. Connect the signal usingprobes to the oscilloscopeAdjust horizontal and vertical position and scale knobs and try to understandtheir effect.Measure the voltage Vpp, Vrms, Vmax, Vmin

Waveform on Oscilloscope:CALCULATIONS:DC COUPLINGAC COUPLINGVpp: 5.041VVpp: 5.041VVVrms: 2.680VVrms: 1.79 VVmax: 4.521 VVmax: 2.52VVmin: -5.201 VVmin: -2.591VBy pressing time, we get the value of frequency and period.Frequency = 2.00kHzPeriod = 500us

Change Coupling to AC:Change Coupling:1.Switch Couplingfrom DCto AC.Observe Changes:2.When you switch to AC coupling, the oscilloscope will block DCcomponents and only show the AC variations of the signal. This oftenresults in the signal being centered around zero volts with any DCoffset removed, leading to potentially different waveform visibility.Short Description of Observations:3.Switching to AC coupling should cause the waveform to appear as acentered signal with the DC offset removed, potentially causing it to beshifted vertically depending on the previous DC offset settings.Task 2: Generate a square wave pulse between 0-5V. Let the frequency be 4KHZ. What is the time period?Time period= 1/f =1/4 =0.25 secDutycycle50%:

CALCULATION:Voltage = 5VFrequency = 4kHzTime = 250us(+) width = 63.0 / 25 =0.25us(-) width = 187.0usDutycycle70%:CALCULATION:Voltage = 5VFrequency = 4kHzTime = 250us(+) width = 175/ 250=0.7us(-) width = 75.0us

Task 3:Frequencyof1kHZ:The sine wave of 1 kHz (note down its value in radians/sec using w = 2πf), 10Vpp.Set up a reference waveform on the oscilloscope and adjust the horizontal position knob to make the live signal 180° out of phase.Measure the time delay.CALCULATIONS:Time delay = -505usw = 2*3.14*1kHzw =6280 rad per sec

Frequencyof3kHZ:The sine wave of 3 kHz (note down its value in radians/sec using w = 2πf), 10Vpp.Set up a reference waveform on the oscilloscope and adjust the horizontal position knob to make the live signal 180° out of phase.Measure the time delay.CALCULATIONS:Time delay = 156.00usw = 2*3.14*3kHzw = 18.84 rad per secFrequencyof3.5 kHZ:The sine wave of 3.5kHz (note down its value in radians/sec using w = 2πf), 10Vpp.Set up a reference waveform on the oscilloscope and adjust the horizontal position knob to make the live signal 180° out of phase.Measure the time delay.

CALCULATIONS:Time delay = -152usw = 2*3.14*3.5kHzw =21.98 rad per secLT spice:A free, high-performance analog circuit simulator developedby Linear Technology.It allows users to design, simulate, and analyze electroniccircuits.Features include:oSchematic capture:Creating circuit diagrams using agraphical interface.oSimulation:Running simulations to observe circuitbehavior.

oWaveform analysis:Examining output waveforms andanalyzing circuit performance.Procedure:Create a simple circuit (e.g., an RC filter) in LT spice.Run a simulation and analyze the output waveform.Modify circuit parameters (e.g., resistor or capacitor values)and observe the changes in the output.Comparesimulationresultswithexperimentalmeasurements.DCoptanalysis:AftersettingNodesusingLabelNet:

DCsweepAnalysisofDiode:GraphofDiode:

DesignProblem:Waveform on Oscilloscope:

Post-LabDiscussion:What are the important features of ammeters, voltmeters, and ohmmeters? Lowinternal resistance:ANSWER:Ammeter:An instrument for measuring either direct or alternating electric current, inamperes. An ammeter can measure a wide range of current values because at highvalues only a small portion of the current is directed through the meter'smechanism; a shunt in parallel with the meter carries the major portion. Voltmeter:A voltmeter, also known as a voltage meter, is an instrument used for measuringthe potential difference, or voltages, between two points in an electronic circuit.Some voltmeters are intended for use in DC circuits; others are designed for ACcircuits. Specialized voltmeters can measure radio frequency voltage. It has highresistance connected in series with a galvanometer. Ohmmeter:An instrument for measuring electrical resistance, which is expressed in ohms. Inthe simplest ohmmeters, the resistance to be measured may be connected to theinstrument in parallel or in series. The main purpose of this instrument is todetermine the resistance of a material.

For the circuits shown below the value values of the resistors should be the last twodigits of your roll number with kilo, mega, or milli your choice.SOLUTION:

Answer the following Questions1-What are the functions of the following buttons: X-Y: X10: LEVELX-Y: Allows you to display one channel's signal on the horizontal axis andthe other channel's signal on the vertical axis for XY mode.X10:Multiplies the horizontal sweep speed by a factor of 10 for zoomingin.LEVEL: Adjusts the vertical position or voltage level of the signal.2-If we change the vertical position of the signal, will it change the amplitude?Changing the vertical position of the signal will not change the amplitude.3-If we change the horizontal position of the signal, will it change theamplitude?Changing the horizontal position of the signal will not change the amplitude

Conclusion:The Digital Oscilloscope, Digital Function Generator, and LT spice software areessential tools for electronic design, testing, and analysis. Each has its strengthsand limitations, making them suitable for different applications. The digitaloscilloscope offers high precision and advanced features, the digital functiongenerator provides versatile signal generation, and LT spice enables accurate anddetailed circuit simulation. Understanding these tools and their critical aspectsenhances their effective use in electronic work.