CATHODE RAY OSCILLOSCOPE Prepared by- RAKESH YADAV

TOPICS COVERED :• Introduction• History• Advancement• Block diagram• Detailed description• Multi –Input Oscilloscope• Types of Oscilloscope• Application

HOW A CRO LOOKS LIKE

INTRODUCTION TO CRO• Versatile electronic instrument giving visual display of signals

• Used for measurement of frequency , amplitude, phase etc.

• Also used in determining the nature and characteristics of various components.

• Has a high bandwidth range thus making it a sensitive and accurate device.

• Easier to use as the internal routine act as a guide to the user.

History• Hand-drawn oscillograms: The earliest method of creating an image of a waveform was through a laborious and painstaking process of measuring the voltage or current of a spinning rotor at specific points around the axis of the rotor, and noting the measurements taken with a galvanometer.

Advancement:

Automatic paper-drawn oscillograph

Cathode ray tubes

Tektronix

OSCILLOSCOPE:The device which convert any electrical signal to visual.(waveform)The graph, usually called the trace, is drawn by a beam of electrons striking the phosphor coating of the screen making it emit light, usually green or blue. This is similar to the way a television picture is produced.

BASIC DIAGRAM

ANOTHER SCOOP….

WORKING OF A CRO

CATHODE RAY TUBE

The main parts of Cathode Ray Tube are:

•Electron Gun Assembly•Focusing Anodes•Deflection Plates Assembly•Screen for CRT

Electr

on Gun

Anodes

Fluorescent Screen

Multi-Input OscilloscopeOscilloscope can have multiple input and display facilities.

The most common one is of - TWO INPUTS.

Although FOUR and EIGHT inputs are available for special applications

Types of oscilloscope:• Single beam oscilloscpe:

• Dual beam oscilloscope:

WHY DUAL TRACE?Unlike single trace oscilloscope , dual trace oscilloscope can display two traces on the screen, allowing you to easily compare the input and output .FOREXAMPLE: input and output of an amplifier.

Amplifier input Amplifier output

Input and output comparison on DTO

Typical Applications:Troubleshoot  electro optical  and electrical systems.Observe a triggered event separately or relative to  the trigger itself.Use with analog light meter output to visualize intensity of a source.Check response of a silicon, InGaAs, or avalanche  photodiode.Analyze signals produced by function generators.Evaluate system performance.