S.SESHA PHANINDHRA 12705A0425 II BTECH ECE-B ANNAMACHARYA INSTITUTE OF TECHNOLOGY AND SCIENCES RAJAMPET (AN AUTONOMOUS INSTITUTION)       S.SESHA PHANINDHRA 12705A0425 II BTECH ECE-B

A SEMINAR ON CATHODE RAY OSCILLOSCOPE

CONTENTS INVENTION OF CRO DEFINITION OF CRO BLOCK DIAGRAM OF CRO EXPLANATION OF EACH BLOCK NECESSITY OF TIME BASE VOLTAGE FUNCTIONS OF VARIOUS CONTROL TERMINALS OF CRO SPECIFICATIONS OF CRO MEASUREMENT OF VARIOUS PARAMETERS USING CRO APPLICATIONS OF CRO CONCLUSION

INVENTION OF CRO: CRO was invented in 1895 by german physicist karl Ferdinand braun

DEFINITION OF CRO: It is an electronic equipment that provides visual images of varying electrical quantities

BLOCK DIAGRAM OF CRO

EXPLANATION OF EACH BLOCK Cathode Ray Tube (CRT): The heart of the CRO is CRT It produces the visual pattern on its screen Vertical amplifier: It amplifies the input signal Time base generator: It is used to deflect the beam in the horizontal section

Horizontal amplifier: It amplifies the sawtooth voltage Trigger circuit: The trigger circuit controls the time base generator and horizontal amplifier Delay line: It is used to delay the signal for sometime in the vertical sections

NECESSITY OF TIME BASE VOLTAGE: If sweep voltage is not applied then only a vertical line will be displayed

FUNCTIONS OF VARIOUS CONTROL TERMINALS OF CRO 1.Time/division: This adjusts the horizontal gain that is width of the pattern. 2.Volts/division: This adjusts the vertical gain that is the height of the pattern. 3.Coupling: It decides the mode of input coupling.

4.Level: This is for selecting the amplitude points on trigger signal at which the time base generator starts the sweep. 5. Horizontal position control: It is for moving the pattern left to right and right to left on the screen 6.Vertical position control: It is used for moving the pattern up and down on the screen

7. Focus: It is for sharp trace on the screen. 8. Intensity: It is for correct brightness of the trace on the screen.

SPECIFICATIONS OF CRO 1. Vertical amplifier: Sensitivity:5m volts/divi to 20 volts/divi Accuracy: + or – 3% Bandwidth: 0 to 20M hz , dc coupling 0.5 hz to 20M hz , ac coupling 2.Horizontal amplifier: Bandwidth:0 to 2Mhz Input impedance:1Mohm/50pf

3.Time base: Sweep ranges:0.1microsecond/div to0.5sec/div Accuracy:+or-5% 4.Triggering: Polarity:positive or negative Max trigger input:250v Input impedance:1Mohm/30pf

MEASUREMENT OF VARIOUS PARAMETERS USING CRO 1.Voltage: No. of verticaldivisions*volts/div 2.Time period: No. of horizontal divisions*time/div 3.Frequency: f=1/Time period

4.Phase: By using lissajous patterns phase can be determined 5.Modulation index: m = (Y2-Y1)/(Y2+Y1) where Y1 is the min voltage level of modulated signal and Y2 is the max voltage level of modulated signal 6.Pulse parameters: Rise time,fall time,pulse width and amplitude of pulse can also be determined

APPLICATIONS OF CRO CRO is extensively used for trouble shooting Examination of waveform Voltage measurement Current measurement Measurement of time interval Frequency measurement Modulation index measurement Pulse measurement Radio applications Scientific applications Engineering applications

CONCLUSION Invention and development of CRO has became a very advantageous in the electronics field as well as in the communication field It is a very useful and versatile electronic laboratory equipment as it is used for measurement of various parameters and as it is having a wide variety of applications

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