Typical CRT Connections:
Figure 7.16 shows various controls and Typical CRT Connections. The following controls are available on CRO panel.
- Intensity It controls the magnitude of emission of the electron, beam, i.e. the electron beam is adjusted by varying the cathode-to-grid bias voltage. This adjustment is (folk by the 500 KΩ potentiometer
- Focus The focusing anode potential is adjusted with respect to the first and final accelerating anodes. This is done by the 2 MΩ It adjusts the negative voltage on the focus ring between —500 V and —900 V.
- Astigmatism It adjusts the voltage on the acceleration anode with respect to the VDP of the CRT. This arrangement forms a cylindrical lens that corrects any defocusing that might be present. This adjustment is made to obtain the roundest spot on the screen.
- X-shift or Horizontal Position Control The X-position of the spot is adjusted by varying the voltage between the horizontal plates. When the spot i$ in the centre position, the two horizontal plates have the same
- Y-shift or Vertical Position Control The X-position of the spot is adjusted by varying the voltage between the vertical plates. When the spot is in the centre position, the two vertical plates have the same potential.
- Time Base Control This is obtained by varying the CT and RT of the time base generator.
- Sync Selector It can synchronise the sweep to signals coming internally from the vertical amplifier or an external signal or the line supply IntExt-Line switch.