Electronic workshop Dr. Imtiaz Hussain URL : Lecture-2 Oscilloscope and Function Generators

Outline – Introduction – Function Generator Waveforms Frequency and Amplitude Setting DC Level – Oscilloscope

Introduction Electronic circuits need to be tested for their functionality. This is done by applying test signals as input to the circuits and observing their response. This requires a device which generates test signals and another device for observing the circuit response to those test signals.

Introduction

Function Generator A Function Generator is a device that is used to generate test signals for testing electronic circuits. All function generators can generate three basic types of waveforms – Sinusoidal – Triangular – Rectangular

Function Generator We can control the amplitude and frequency of generated waveforms.

Function Generator We can also control the DC level of generated waveforms.

Function Generator

Function Generator Probes

Oscilloscope The oscilloscope is basically a graph-displaying device It draws a graph of an electrical signal. In most applications the graph shows how signals change over time: – the vertical (Y) axis represents voltage – the horizontal (X) axis represents time.

Example Electrical Signal Above, this sine wave represents a voltage that is changing over time So at time=2.5s, what is the voltage? – And again at 10seconds?...15 seconds? We can see that as time moves forward, the voltage is changing – Is this an AC or DC voltage? What does that mean? X=TIME (seconds) Y=VOLTAGE (volts)

What are the major components? Display Screen – Displays an input signal with respect to time. Control Panel – Adjusts how the input signal is displayed.

What is the purpose of an oscilloscope The purpose of an oscilloscope is to measure a voltage that changes with time and show it in a graphical format 1)Here is the oscilloscope in our lab -Notice the X-Y axes 2) Here is our alternating voltage signal from before 3) If we measure our signal with the scope, it would look like this!

Oscilloscope Screen Notice that the screen has ruled divisions both horizontally and vertically. The major divisions are marked off in centimeters, the middle lines also have minor divisions every 0.2 of a centimeter.

Oscilloscope Probes

Oscilloscope Problem Using the function generator, create a wave with the following output: – 3 kHz Frequency – Sinusoidal Shape – 2 Volt Amplitude – D.C Offset 0 Adjust the output so that only 2 complete cycles are showing. When are you finished, call your tutor to inspect it.

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