Introduction What is an oscilloscope 1 Introduction l

Introduction • What is an oscilloscope? 1

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

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

Control panel of an oscilloscope l l l Vertical Section Horizontal Section Trigger Section 4

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

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

Digital oscilloscope l Capture and view events l Digital storage oscilloscope (DSO) 7

Digital oscilloscope (contd. ) l Sampling l Interpolation 8

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

Probes l Components 10

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

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

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