Question:I want to have some exterior security cameras show their picture on a
UK domestic TV when a PIR motion alarm senses movement in their
viewing area, cutting off the normal TV programme. Either full frame
picture (preferably) or picture in picture. Ideally the cameras would
be recording to slow frame recorders at all times, but only impose on
domestic TV when movement is sensed.
Possible? Expensive? Manufacturers? Self build?
Any help / pointers appreciated.
Answer:I just recently designed a system to do (almost) precisely this. You can
use a regular high quality time lapse recorder, a digital multiplexer and
several cameras to generate continuous recording of 4, 9 or 16 areas at
once. A digital TLR, such as Panasonic's new toy, may prove better though.
Although you can use video motion detection, it tends to get pricey.
Depending on how sensitive or selective you want the motion detectors to be,
you may be able to use simple outdoor PIRs such as are used in motion light
fixtures.
Set the multiplexer to home (that is, go full screen) to the camera where
motion is detected for a few minutes. Also, by connecting the various PIR
outputs to a common relay (with diodes to prevent back feeding the other
home triggers) you can trip a Xantech 590-00. This unit stores up to 16 IR
commands or sequences of commands and plays them back when there is a
contact cl;osure. Use the IR to tell the TV to switch to a particular
unused channel. The video output (loop through) of the TLR can be modulated
by a ChannelPlus unit, making whatever is being recorded at any given time
available to all TVs in the home as a dedicated in house channel.
