Videolarm qfdpt3-50na 用户指南
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Power Supply
Power A
Power B
Camera
Assembly
Assembly
Primary
Power
Power
Video Signal
Video Shield
Monitor
(Ground Return)
Figure A Ground Loop
TROUBLESHOOTING
If you experience problems with the camera picture please check
these simple troubleshooting procedures for possible solutions before
calling technical support.
these simple troubleshooting procedures for possible solutions before
calling technical support.
IMPORTANT NOTE: If you have removed the ground loop and
the horizontal line still remains on screen
call Videolarm technical support for further
information.
the horizontal line still remains on screen
call Videolarm technical support for further
information.
GROUND LOOPS
Generally a horizontal line on screen, whether moving or stationary,
means you have a ground loop problem. The video shield should
only be connected to ground through the monitor or other electronic
equipment that uses the video signal. Connecting the video shield to
ground at the camera will create a ground loop, which may interfere
with the video signal (See Figure A). This should not damage the
camera, but the video signal may become unusable. A ground loop
problem will cause a dark horizontal bar to slowly “scroll" through the
picture. To solve this problem, remove all ground connections from the
video connection EXCEPT for the ground at the terminating end of
the video signal.
Generally a horizontal line on screen, whether moving or stationary,
means you have a ground loop problem. The video shield should
only be connected to ground through the monitor or other electronic
equipment that uses the video signal. Connecting the video shield to
ground at the camera will create a ground loop, which may interfere
with the video signal (See Figure A). This should not damage the
camera, but the video signal may become unusable. A ground loop
problem will cause a dark horizontal bar to slowly “scroll" through the
picture. To solve this problem, remove all ground connections from the
video connection EXCEPT for the ground at the terminating end of
the video signal.
The video termination should be a 75-ohm impedance, standard in
monitors and other video equipment. If the video signal goes to more
than one piece of equipment, a monitor and multiplexer input for
instance, insure that one and only one piece of equipment terminates
the video signal with 75 ohms; otherwise the image will be degraded
and may appear to be unusually dim.
monitors and other video equipment. If the video signal goes to more
than one piece of equipment, a monitor and multiplexer input for
instance, insure that one and only one piece of equipment terminates
the video signal with 75 ohms; otherwise the image will be degraded
and may appear to be unusually dim.
STATIONARY OR SCROLLING HORIZONTAL
LINES ON SCREEN
LINES ON SCREEN
PICTURE IS CLEAR, LOW OR NO COLOR;
PICTURE IS DARK OR GRAINY IN GOOD
LIGHTING CONDITIONS
PICTURE IS DARK OR GRAINY IN GOOD
LIGHTING CONDITIONS
The auto iris lens is set at the factory. If you experience video
too light or dark you can manually adjust using the auto iris
adjustment screw.
too light or dark you can manually adjust using the auto iris
adjustment screw.
If there is low or no color the Auto Iris is too open, if the picture is
dark or grainy in good conditions the Auto Iris is too closed.
dark or grainy in good conditions the Auto Iris is too closed.
To adjust the auto iris lens, fi rst locate the AUTO IRIS ADJUSTMENT
SCREW on the camera PC board. Using a small insulated
screwdriver (blade width of from 1/16" to 3/32"), adjust the control.
Turning the control CLOCKWISE opens the iris, making the image
brighter.
Turning the control COUNTER CLOCKWISE closes the iris, making
the image darker.
SCREW on the camera PC board. Using a small insulated
screwdriver (blade width of from 1/16" to 3/32"), adjust the control.
Turning the control CLOCKWISE opens the iris, making the image
brighter.
Turning the control COUNTER CLOCKWISE closes the iris, making
the image darker.
Auto Iris
Adjustment Screw
Adjustment Screw
Figure D
AUTOMATIC BROWN OUT FEATURE
The camera includes an automatic brown out feature which is acti-
vated whenever the incoming voltage drops below 10 VAC or VDC.
vated whenever the incoming voltage drops below 10 VAC or VDC.
IMPORTANT NOTE ON AUTO IRIS ADJUSTMENT:
WHEN ADJUSTING, USE A SMALL, INSULATED SCREW-
DRIVER.
DRIVER.
The auto iris adjustments are very sensitive. Use
gentle pressure when turning. To adjust, turn either clock-wise or
counter-clockwise no more than one degree at a time. Check the
monitor after each turn to determine is the desired brightness and
color have been obtained. When the adjustment is satisfactory,
place a hand over the lens to block out all light. Quickly remove
the hand to be sure the iris reacts.
counter-clockwise no more than one degree at a time. Check the
monitor after each turn to determine is the desired brightness and
color have been obtained. When the adjustment is satisfactory,
place a hand over the lens to block out all light. Quickly remove
the hand to be sure the iris reacts.
LINE LOCK
All cameras are all shipped from the factory with the line lock function
disabled. If your application requires Line Lock contact Videolarm.
Auto Iris
Adjustment
Screw
Adjustment
Screw
SERIAL NUMBER CB CAMERAS
SERIAL NUMBER MC CAMERAS
Figure C
Auto Iris
Adjustment
Screw
Adjustment
Screw
Figure E
SERIAL NUMBER CT CAMERAS
Figure B
SERIAL NUMBER YK CAMERAS
Auto Iris
Adjustment
Screw
Adjustment
Screw