An oscilloscope is a graph-displaying device used to measure electrical signals over time. It displays voltage on the y-axis and time on the x-axis, allowing observation of signal behavior. Oscilloscopes provide information about time, voltage, frequency, rise and fall times, and other signal characteristics. The device has vertical, horizontal, and trigger sections to control measurement settings. Analog oscilloscopes provide real-time signal display, while digital oscilloscopes can store and replay signals. Probes connect the oscilloscope to circuits and come in passive and active varieties with different characteristics for measuring voltage signals.

1. Introduction
• What is an oscilloscope?
1

2. Introduction

A graph-displaying device of electrical signal



X axis: Time
Y axis: Voltage
Z axis: Intensity or brightness
2

3. Introduction

Information given by oscilloscopes






Time and voltage
Frequency and phase
DC and AC components
Spectral analysis
Rise and fall time
Mathematical analysis
3

4. Control panel of an
oscilloscope



Vertical Section
Horizontal Section
Trigger Section
4

5. Basic setting

Vertical system


Horizontal system


attenuation or amplification of signal (volts/div)
The Time base (sec/div)
Trigger system

To stabilize a repeating signal and to trigger on a single
event
5

6. Analog oscilloscope


Real-time display of signals
Block diagram


Sweep generator and vertical amplifier
Earthquake recorder
6

7. Digital oscilloscope

Capture and view events

Digital storage oscilloscope (DSO)
7

8. Digital oscilloscope (contd.)

Sampling

Interpolation
8

9. Advantage of Digital Scope







Trend towards digital.
Easy to use.
One-shot measurement
Recoding
Triggering
Data reuse
Connectivity
9

10. Probes

Components
10

11. Probes
High quality connector
 High impedance (10M )
 50 for high frequency measurement

11

12. Passive probe


10 attenuation
 Good for low circuit loading
 Suitable to high frequency signal
 Difficult to measure less than 10mV
signals
1 attenuation
 Good for small signals
 Introducing more interference
12

13. Active probe
Signal conditioning ⇒ oscilloscope
 Require power source
 Good for high speed digital signals over
100MHz clock frequency

13