Security System...under attack in South Africa

Hi There Guys,

I was hoping you could help me with the following:

Being situated in the highest crime ridden city in the world Johannesburg South Africa and having a number of armed robberies i felt it was time to create my own surveillance and security system. As the ones provided by security companys here provide little assistance.


My aim is to create a series of PIR motion detectors with built in still cameras ( http://www.defensedevices.com/motion-detection-camera.html) and link them to a DVR and then to a LCD ( **broken link removed**) . However i have run into the following problem.

The DVR (**broken link removed**) only has 2 video inputs. Would it be possible to link all 6 or more PIR motion detectors to one common video input? And would the above components work together? Or do you perhaps have any other suggestions as to how i could setup up a early warning system around my house with a affordable budget in mind?

I'll appreciate any response to my problem and thank you for your time and help.

Kind Regards,
Reinier

What you describe is passive security system - it will just record on the tape or HDD the intruders... so what, it's doubtfull that you'll find them later. You need active security system, system which protects you (pushes gas, electricity, etc.).

Hi Luben,

Not really passive, you see what i'm hoping for is that once the PIR sector has been breached a alarm will ring alerting me to the LCD screen which i'll have stationed in all the main rooms...once i've seen what breached the sector, i'll proceed with the necessary actions.

The only 2 problems i have is......

1) Can i link all 6 PIR to one common video input?
and

2)Have 6 seperate PIR cables running to an alarm control panel indicating which sector was breached?

Thanks

Yes you can link all six video inputs into one. The usual method is to use a silicon switch like the 4066. These analog switches have control lines. You need some logic to select the alarmed sector with the proper switch to your LCD display.
Very similar switching is what is used to make the KVM switches that allow two computers to connect to one monitor, mouse and keyboard. (I think KVM means Keyboard, Video, Mouse).

Find an old KVM switch and dismantle it. You will probably have sufficient parts for all the switches you need since you will not need to switch keyboard and mouse.

Check out this web site also for ideas.
https://www.engadget.com/2006/09/05/how-to-make-a-component-video-switch/

Excellent! Thanks Banjo..will have a look.

May be a little delayed answer, but if U still needs help, pls. let me know.

Regarding PIR sensors, the usual way is to connect the relay contacts that are NC, in series, then, when any sensors triggers, it´s relay will open the contact and of course, the complete circuit ( loop ) will open indicating an alarm condition. A pitfall of this scheme is that if there is a faulty sensor, you will need to check one by one to find the faulty one. In alarm panels, the alarm inputs are called ZONES. If U connect one sensor per zone and U find a faulty sensor, the panel allows to bypass the zones and the systems continues monitoring the other sensors.

Well there is a lot I can say about this, so if U need further assistance, pls let me know.
Best regards