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

2. A SEMINAR ON CATHODE RAY OSCILLOSCOPE

3. 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

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

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

6. BLOCK DIAGRAM OF CRO

7. 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

8. 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

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

13. 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.

14. 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

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

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

17. 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

18. 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

19. 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

20. 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

21. 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

23. ANY QUERIES