Cathode Ray Oscilloscope

Cathode Ray Oscilloscope:

Cathode Ray Oscilloscope:

 Is is very versatile device. it is in fact a high speed graph plotting device.
 is displays the shape or size of an electrical signal on the screen. I is provides
 visual images of varying electrical quqantities. aslo, it provides accurate time
 and amplitude measurements of voltage signals over a wide rang of frequencies.

 Principle:

  When a charged a particle moves in an electric field, a force acts on it.

 Construction:

  A cathode ray oscilloscope consistes of ;

                1)  electron Gun                           
                2) Deflection system
                3) Display system

1) Electron Gun

 .  The electron gun products a beam of electrons. it consist of;

. Filament

 .   When current is passed through the filement, it glows and heat from it heats up the cathode.

. Cathode

 .   When cathode is heated, is emits electrons by thermionic emission.

.Grid

.    It is at negative potential relative to cathode. it controls the number of electrons reaching
  the screen and thus control the brightness of spot on the screen.

.Focusing Anode

.   It is at positive relative to cathode. The electrons that pass through this anode are focused
  into a fine beam.

. Accelerating Anode

                    It is at zero potental. Its main function is to accelerate the electrons.

2) Deflection System:
                                  . The beam of electrons from anodes firstly passes through a paid of horizontal deflecting plates called X plates which deflect the beam horizontally on the screen i.e.,
paralles to X axis and then between two vertical plates called Y plates which deflect the beam
vertically on the screen i.e., along the Y axis.

3) Display System:
                                                           The screen of cro is coated with a fluorescent meterial
the zinc sulpoide gives a glow of light when electrons collide with it.

. Working Of CRO
                                 The voltage that is applied across the X plates is usually provided by a circuit that is built in CRO (know as time base generater).