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| High Voltage Power Supply |
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| Outputs | Description |
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| VDFOCUS | Parabolic waveform of vertical frequency. |
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| HDFOCUS | Parabolic waveform of horizontal frequency modulated by the |
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| VDFOCUS waveform. |
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| /HVEN | Enable signal for HVPS, used to shut down HVPS for CRT |
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| System Power Supply |
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| Inputs | Description |
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| +5V | Power supply to digital components. |
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| GND | Return from digital components. |
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| +15V | Power supply to analog components. |
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| Power supply to analog components. |
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| GND (TP 0) | Return from analog components. |
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Interlocks and Protection
Input
/SWEEPOK
TTL high indicates that one or more of the sweeps, either horizontal or vertical is not at or above the minimum amplitude and frequency. This will cause a cutoff so that RVOUT, GVOUT, and BVOUT will be pulled low. Additionally, /RENABLE, /GENABLE, and /BENABLE will be pulled high resulting in shutdown of grid bias at the Video Output Boards. Also, the SWEEPOK status bit will be transmitted to the SCB.
RBEAM
Signal representing average red CRT beam current at 1mV/1uA. At greater than 0.7V, causes contrast and overlay intensity on all three colors to be reduced.
GBEAM
Similar to RBEAM.
BBEAM
Similar to RBEAM.
/RVIDOK
High indicates low voltage at the +100V supply on the red Video Output Board. This causes a low at the VIDOK status bit sent to the SCB over the IIC. The /HVEN signal is allowed to go high shutting down the HVPS. Additionally, a high cutoff signal is sent so RVOUT, GVOUT, and BVOUT will be pulled low. /RENABLE, /GENABLE, and /BENABLE are also pulled
Model 330, 340SC and 370SC Service Manual |
