The document discusses the cathode ray oscilloscope (CRO). It begins with an introduction that describes a CRO as an electronic device that uses a cathode ray tube to generate visible patterns and graphs on a screen. It then provides details about the basic blocks of a CRO including the vertical and horizontal amplifiers, trigger circuit, time-base generator, and cathode ray tube. Applications of CROs include viewing waveforms, measuring frequency and voltage, and circuit design and testing. Advantages include high resolution and contrast while disadvantages include size, power consumption, and complexity.

1. CATHODE
RAY
OSCILLOSCOPE

2. PRESENTED BY-
 SUSHIL KUMAR SINGH
 LAKSHMI
 SIDDHARTH YADAV
 MRIGANKA BHATTACHARJEE
 KRISHNA KUMAR BHARGAV
(dedicated to Almighty god)
2
UNDER THE GUIDENCE OF –
UPMA DAS
16 May, 2017

3. CONTENTS-
 INTRODUCTION
 BLOCK DIAGRAM OF CRO
 CALCULATION
 CATHODE RAY TUBE
 ADVANTAGES / DISADVANTAGES
 APPLICATIONS
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4. INTRODUCTION-
CRO is an electronic device containing a cathode ray tube(CRT)
that generates an electron beam that is used to produce visible
patterns, graphs on a phosphorescent screen.
HISTORY :
The first CRO was developed by German
physicist Ferdinand Brawn in 1897.
CRO is a common laboratory instrument that
provides accurate time and amplitude Measur-
ement of voltage signal over a wide range of
frequency .
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5. FIG:EXTERNAL VIEW OF CRO
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6. TYPES OF CRO-
 ANALOG CRO :
It is the simplest and earliest type of oscilloscope comprises of a
vertical amplifier, a cathode ray tube, time base, a power supply
and a horizontal amplifier. These are commonly known as analog
CRO.
 DIGITAL CRO :
It is a complex electronic device composed of various software
and electronic hardware modules that work together to capture,
process, display and store data that represents the signals of
interest of operator.
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7. BASIC BLOCKS OF CRO-
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8. BLOCK DISCRIPTION-
 VERTICAL AMPLIFIER:
The input signals are amplified by vertical amplifier to
make the waveform compatible for operation.
We can obtain the sensitivity of oscilloscope by vertical
amplifier. The sensitivity of an oscilloscope (in V/div.) is
directly proportional to the gain of the vertical amplifier.
 TRIGGER CIRCUIT:
The signals which are used to activate the trigger circuit are
converted to trigger pulses for the precision sweep operation
whose amplitude is uniform. Hence input signal can be
synchronized.
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9.  TIME-BASE GENERATOR:
The Time-base circuit uses a Transistor, which is used to
produce the ramp voltage. The ramp voltage produced by
this circuit is required to deflect the beam in horizontal
section.
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FIG:-Sweep circuit and ramp voltage diaram 16 May, 2017

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 HORIZONTAL AMPLIFIER:
The ramp voltage produced by the time base
generator is amplified by the horizontal
amplifier ,before it applied to horizontal
deflection plates.
 Delay Line:
The Delay line retards the arrival of the
amplified waveform obtained from vertical
amplifier to reach to the vertical plates.

11. BASIC CRO CIRCUIT-
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 BLANKING CIRCUIT:
While retracing the horizontal line from left to right, the
movement of spot will appear as a thin and dim line. Ideally it
should be invisible, so to make it invisible a circuit provided
known as blanking circuit.
 CALIBRATION OSCILLATOR:
Some laboratory oscilloscopes having internally generated input
voltage of known voltage which is provided by this oscillator
circuit.

13. CALCULATION
FORMULA1
Voltage(V)= (no.of division) X (*ch1).
Peak voltage=2V
Where:*ch1 is the VOLTAGE/DEVISION
Value Of the waveform.
FORMULA2
Time period= (no.of division) X (TB).
Where: TB is the TIME/DEVISION
 Volt=1*5 =5volt.
 Time =(.2 ms)*2 =(.4 ms)
frequency=1/(.4ms)
=2.5 kHZ13
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14. CATHODE RAY TUBE -
 It consist of THREE major portion-
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15. ELECTRON GUN:
Electron gun tube is the source of electron which emits electron with very high ENERGY
& acceleration/
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16. ANODE PLATES(focusing & accelerating)
++ ++ ++++ ++
---------------------------------------------
++ ++ ++ ++
 Function of Anode plates is to give a ACCELERATION and a
particular direction to e’ beam.
 The supply voltage is very high (1500)v.
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17. 17

18. DEFLECTING PLATES
There are two types of deflecting plate-
1. VERTICAL DEFLECTING PLATE- resposible for
y axis portion of graph.
1. HORIZONTAL DEFLECTING PLATE- resposible
x axis portion of graph.
1.
1.
2. Vertical charge plate 2.Horizontal charge plate 18
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20. Animation of Cathode ray
tube:
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21. FLUORESCENT SCREEN:
 Fluorescent screen is a transparent screen
Coated with Fluorescent material
( phosphorus ).
 Phosporous emit low frequency
(visible spectra) light when it
absorb the kinetic energy of
electron.
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22. SUMARRY OF CRT
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23. ADVANTAGES OF CRO-
 RESOLUTION AND ASPECT RATIO-
IT OPERATES AT ANY RESOLUTION,GEOMETRY AND ASPECT
RATIO WITHOUT THE NEED FOR RESCALING THE IMAGE.
 HIGHEST RESOLUTIONS-
IT RUNS AT THE HIGHEST PIXEL RESOLUTIONS GENERALLY
AVAILABLE.
 HIGH CONTRAST LEVEL-
IT PRODUCES HIGHEST CONTRAST LEVEL SUITABLE FOR USE
EVEN IN DIMLY LIGHT OR DARK ENVIRONMENT.
 FAST RESPONSE-
CRT GIVES FAST RESPONSE TO THE SIGNAL SO IT IS BEST FOR
A RAPIDLY MOVING AND CHANGING WAVE.
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24. DISADVANTAGES OF CRO-
 VERY SENSITIVE-
SENSITIVE DEVICE AND REQUIRES COMPLETE
ISOLATION FROM NOISE PRONE RESOURCES.
 PHYSICAL-
THEY ARE VERY LARGE ,HEAVY AND BULKY.THEY CONSUME A LOT OF ELECTRICITY
AND PRODUCE A LOT OF HEAT.
 BRIGHTNESS-
RELATIVELY BRIGHT BUT NOT AS BRIGHT AS LCD’S. ITS NOT SUITABLE FOR VERY
BRIGHTLY LIT ENVIRONMENT.
 CONTROL TERMINALS-
THERE ARE LOTS OF CONTROL TERMINALS OVER THE CONTROL PANEL THAT
LEADS TO A GREATER COMPLEXITY OF THE DEVICE MAKING IT DIFFICULT TO USE.
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25. USE & APPLICATION OF CRO
 TO SEE THE WAVEFORMS- we can see the waveform of
input signal with the help of CRO.
 FREQUENCY MEASUREMENT-Using a CRO we can
determine the frequency of the unknown waveforms.
Mathematically: (y axis value X CH*)=T(time period)
So, Frequency=1T.
 VOLTAGE MEASUREMENT- Y AXIS of waveform give the
amplitude value of input signal in volt.
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26.  IT IS USE IN DESINE OF NEW CIRCUIT- CRO is strictly
advise to see the exact output of new develop circuit. And to
check the defective components in new circuit.
 IT IS BASICALLY USE IN SCIENTFIC AND ENGINEERING
APPLICATIONS.
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27. REFRENCES:
 AK SAWHNEY-Electronic instrumentation and
measurement
 H.S KALSI-Electronic instrumentation and
measurement
 DAVID A.BELL-Electronic instrumentation
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