Chapter 2---System Description
V_VIC #2
Similar to V_VIC #1
V_VIC #3
Similar to V_VIC #1
/SEL_VIC #1
Input signal from RGB VIC board which is used to select
input video source from VIC #1.
/SEL_VIC #2
Similar to /SEL_VIC #1
/SEL_VIC #3
Similar to /SEL_VIC #1
LOW VOLTAGE POWER SUPPLY
INPUTS
DESCRIPTION
+ 5.1 volts
Power supply to digital components
+ 15 Volts
Power supply to analog components
- 15 Volts
Power supply to analog components
2.3.5 Video Amplifier
The Video Amplifier Board (VAB) is located at the back side of the
projector under the necks of the three CRTs. It contains three
separate video amplifiers, one each for red, green, and blue. The
outputs from these video amplifiers connect directly to the CRTs
and provide all electrical connections to the CRTS except for the
anode voltages.
The following functions are provided by VAB:
•
Amplification of video signals and driving the cathode of all
three CRTs
•
Sensing the cathode beam current for all three CRTs
•
G1 regulator for all three CRTs
•
Blanking drive section
•
Phosphor protection for all three CRTs
•
G2 regulator and adjustment of black level (screen) for all
CRTs
•
DC restoration for the video signals
•
CRT interface for focus, heater voltage and ARC ground
The Video Amplifier Board I/O diagram (Figure 2-11) and the list
of Inputs and Outputs (Table 2-10) provide information for the
technician to perform module level troubleshooting.
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Model 220 Service Manual
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Страница 1: ...SERVICE MANUAL Model 220 Projector ...
Страница 10: ...Safety Information Model 220 Service Manual x ...
Страница 14: ...Chapter 1 Introduction 1 4 Model 220 Service Manual ...
Страница 20: ...Chapter 2 System Description Figure 2 1 Optical System Block Diagram 2 6 Model 220 Service Manual ...
Страница 119: ...Chapter 4 Maintenance Removal Replacement 4 26 Model 220 Service Manual ...
Страница 129: ...Chapter 5 Troubleshooting 5 10 Model 220 Service Manual ...
Страница 140: ...Glossary Model 220 Service Manual B 5 ...