Hitachi DV-P345E, Руководство по обслуживанию

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15
16
à
Fast Blanking
17
à
Video Gnd
18
à
Fast Blanking Gnd
19
à
Composite Video In
20
à
Composite Video Out
21
à
Shield
Some cheaper SCART cables use unshielded wires, which is just about acceptable for
short cable lengths. For longer lengths, shielded co-ax cable become essential.
Scart Signals:
Audio signals
0.5V RMS, <1K output impedance, >10K input impedance.
Red, Green, Blue
0.7Vpp ± 2dB, 75R input and output impedance. Note that the Red connection (pin 20) can
alternatively carry the S-Video Chrominance signal, which is 0.3V.
Composite Video / CSync
1Vpp including sync,
±
2dB, 75R input and output impedance.Bandwidth = 25Hz to 4.8MHz for
normal TV Video de-emphasis to CCIR 405.1 (625-line TV)
Fast Blanking
75R input and output impedance. This control voltage allows devices to over-ride the composite
video input with RGB inputs, for example when inserting closed caption text. It is called fast
because this can be done at the same speeds as other video signals, which is why it requires the
same 75R impedances.
0 to 0.4V : TV is driven by the composite video input signal (pin 19).
Left unconnected, it is pulled to 0V by its 75R termination.
1V to 3V : the TV is driven by the signals Red, Green, Blue and composite sync. The
latter is sent to the TV on pin 19. This signal is useful when using a TV to display the
RGB output of devices such as home computers with TV-compatible frame rates. Tying
the signal to 5V via 100R forms a potential divider with the 75R termination, holding the
signal at around 2V. Alternatively, if a TTL level (0 to 5V) negative sync pulse is
available, this will be high during the display periods, so this can drive the blanking signal
via a suitable resistor.
Control Voltage
0 to 2V = TV, Normal.
5 to 8V = TV wide screen
9.5 to 12V = AV mode
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