SCART AUTO VIDEO SWITCH
This project takes advantage of the scart sockets video select function to switch to the scart channelon a TV when a contact is closed, this can be from a wide variety if devices ranging from a PIR sited near a cctv camera to a reed switch in a door that is within a cctv cameras view. Alternatively this project can be used to switch to the scart channel on some TVs that do not have the ability to manuallyswitch to the scart channel.
It should be noted that this project has not been tested with scart splitter boxes.
All that is required to switch to the scart channel is to apply between 8-15v to pin 8 of the scart plug.
The diagram below shows a typical scart plug pin layout
The basic circuit diagram is shown below:
The only pins used in the scart plug are:
pin 8, Function Select
pin 20, video IN
pin 17, Video GND
pin 21, Common GND
pin 8, Function Select
pin 20, video IN
pin 17, Video GND
pin 21, Common GND
The above circuit can be used 'as-is', all that would be needed is a scart plug, a plug in transformerwith a 8-12v output and a switch mounted on the scart plug, however the switch would need to be on aremote lead so that crawling behind the TV to switch the scart channel can be avoided.
The prototype was mounted inside a small project box on a short (50cm) lead connecting it to the scart plug. An LED mounted on the front panel shows when the switch has been triggered, roll your mouse over the image below for an example.The trigger is supplied by a 3.5mm mono jack, if the plug is connected the scart is switched.
Inside the box is a relay that switches the 12v to pin 8, the trig. socket can then be switched by any device with an output that closes when the device activates.
