CRO4

The Cathode Ray Oscilloscope (CRO)

Three parts of the CRO:
1. Electron gun

• Filament: Is heated when current flows through it. It is used to heat up the cathode.
• Cathode: Heated cathode emits electrons through the process of thermionic emissions.
• Control grid: Control the number of electrons in the electron beams.
  The more negative the grid, the fewer the electrons are emitted from the electron gun and the less the brightness of the bright spot on the screen.
• Focusing anode: To focus the electrons into a beam and to attract electrons from the area of the control grid.
• Accelerating anode: To accelerate the electron beam towards the screen.

2. Deflection system

• The deflection system allows the electron beam to be deflected from its straight-line path when it leaves the electron gun.
• Y-plates is to move the electron beam vertically up and down the screen when an input voltage is applied across it.

3. Fluorescent screen


Application of CRO

1. Measuring potential difference
2. Measuring short intervals
3. Displaying wave forms