This post is part of the series Chapter-1 Applied Electronics
Other posts in this series:
Question: What is CRT? How does it work? Explain its working with diagram
- CRT is the heart of CRO. It is made up of thick glass and evacuated.
- The filament, cathode and control grid form the electron gun.
- It produces diverged beam which is accelerated and focused by the pair of pre-accelerating and second accelerating anodes.
- They are separated by focusing anode to make electron beam narrow.
- The beam is deflected vertically by vertical deflection plates and horizontally by horizontal deflection plates.
- The screen is coated with fluorescent material (phosphor). The beam strikes on the screen. The phosphor absorbs kinetic energy of beam and re-emits it as light energy to produces bright spot.
- After striking, some electrons bounce back known as secondary electrons. They are absorbed by aquadag coating in funnel shape of CRT, electrically connected to focusing anode.
- All electrodes are internally connected to pins for external connection.
- The screen of CRT is marked with graticule or x-y scale of 1 sq. cm. for measurement.
Continue reading this series:
Electrostatic Focusing System