What do I use to switch cameras on a mobile vehicle?
MOBILE VIDEO SWITCHING APPLICATIONS VS-12
By: Don McClatchie
FM SYSTEMS, INC.
This article discusses several applications where the VS-12 is used to enhance the operation of a mobile video system. The VS-12 VIDEO SWITCHER is a 2X1 video switch controlled by 12 Volt DC power connected to the two screw terminals on the unit. Standard BNC connectors are used for the video inputs and output, and a screw terminal connector is used for the DC power.
The first case involves a horse trailer used to transport horses. The customer has a rear facing video camera for back-up assistance and a camera mounted inside the trailer to monitor the horses during transport. By connecting the VS-12 to the back-up lights circuit they were able to have the back-up camera connected to the dashboard monitor when the transmission was in reverse (backing up the vehicle), and during normal driving the horse monitor camera would automatically be connected to the monitor. This arrangement makes the video switching completely automatic and hands free.
The next application is used on a municipal vehicle fire truck. The fire truck is equipped with two video cameras and a DVR to record the scene. One camera was directed out the front windshield of the truck to view the traffic and maneuvering of the truck going to and from the scene of the fire. The second camera was mounted on the truck facing the pump controls and the surrounding area. The VS-12 video A/B switch was connected to the two cameras and the relay power was connected to a switch on the shifting mechanism. When the truck transmission was in drive the forward facing camera was recorded and when the transmission was not in drive the other camera was connected to the recorder. This allowed the recording to take place as desired without the need for manual switching.
In the field of RV’s Recreational Vehicles there are many applications for switching video signals. Some RV’s have a video camera facing out the front windshield so that passengers can see the driver’s view of the road or switch to other programming. Of course if a back-up camera is in use there is still the automatic switching for the driver to consider.