Hello friends In this article we will know what is cathode ray oscilloscope? And what does it do? And how does it work? Know about what is a cathode ray tube and what is the formula for its beam deflection and many facts related to it.
cathode ray oscilloscope
A cathode ray oscilloscope provides a visual display of time varying electrical signals. The CRO is actually an XY plotter in which the cathode rays act as a pencil and the coating of a phosphorescent material on the screen of the CRO acts as a sheet on which plots or graphs are made. When the cathode rays hit the phosphor screen, a bright spot is produced on the screen.
In a typical CRO, a horizontal input is used which is a ramp. voltage (ramp voltage). It is also called time base or saw-tooth voltage. This voltage drives the bright spot in the horizontal direction on the screen. A vertical input voltage is given to the CRO. It is the voltage that we have to see or analyze on the screen.
What is a cathode ray oscilloscope called?
On the oscilloscope the waveforms of the signals ranging from very low frequencies (DC to 20 Hz) to very high frequencies (1 Hz) can be seen directly. In CRO all the graphs (patterns) are generated on the screen of a tube called Cathode Ray Tube it is said. In other words, “cathode rayAn oscilloscope is an instrument commonly used in the laboratory to display, measure, and analyze various waveforms of electrical circuits. ,CROProvides a visual display of electrical signals that change over time
Cathode Ray Tube –
The structure of a cathode ray tube (CRT) is shown in Fig.
CRT has three main parts –
- Electron gun
- Deflecting system
- Fluorescent screen
The brief working mechanism of CRT is as follows –
The electron gun produces a sharp and focused beam of electrons. This beam is focused by the accelerating anode and focusing anode and strikes the fluorescent screen with high velocity and energy when a luminous point is produced on the screen.
After leaving the electron gun, the electron beam passes between two pairs of electrostatic deflection plates.
The deflection of the beam occurs when voltage is applied to these plates. The voltage applied to one pair causes the beam to go up and down and the voltage applied to the other pair deflects the beam horizontally. These two horizontal and vertical motions of the beam depend on each other so the beam can be fixed in any part of the screen.
All the electrodes of the cathode ray tube are sealed in an evacuated glass envelope. The connections to the electrodes are made through pins on the outside of the tube. The CRT is connected to the circuit by plugging it into a suitable base.
Deflection of Beam –
Beam deflection in CRT is given by the following formula –
D = LldVd/2d Va
- Here, D = deflection on the phosphor screen
- L = distance of the screen from the center of the deflection plates
- ld = effective length of deflection plates
- d = distance between deflection plates
- Vd = deflection voltage
- Va = accelerating voltage
What is the full form of CRO?
CRO full form – Cathode ray oscilloscope
What is the full form of CRT?
CRT full form – Cathode ray tube