Pinch PIR signal from alarm to drive timer relay

Discussion in 'Electricians' Talk' started by MinionBob, Jan 7, 2022.

  1. MinionBob

    MinionBob New Member

    Greetings. I’m seeking some spark wisdom on my mini project.
    Looking to borrow signal from one of the PIR sensors feeding my alarm to turn on a CCTV connected screen via a 12v timer relay so the screen will come on when someone enters the corridor then turn off 20sec after they leave.
    I have a working telecom elite something alarm with lots of stuff wired into it.
    I can probably figure out which PIR wire I need by having my kids jump in front of the sensor whilst I am using a tester on the panel.

    I picked up one of 12v relays which I am sure will come without instructions but it is labelled.

    and a junction box to hide it all in.

    seems like relay can control both AC and DC. The monitor has external power supply so I could wire it into either. I prefer DC to reduce latency. Screen has 44w max power draw which seems to be within DC rated load.
    I will pick up some tails to create an extension from the power supply and run it into the relay inside the junction box and run a 12v signal there too.
    Does it work as a plan?
    How do I go about splitting the PIR wire on alarm side and wiring up the relay?
    Last edited: Jan 7, 2022
  2. Teki

    Teki Screwfix Select

    Why not configure one of the auxiliary outputs on the Elite panel or from the keypad if it is closer to your CCTV system?

    This is assuming you have engineer code access to your system.
  3. FlyByNight

    FlyByNight Screwfix Select

    As suggested, use a programmable ouput, set to Zone Mimic as te trigger.

    Which panel do you actually have? 24, 48, 64W, 88?
  4. MinionBob

    MinionBob New Member

    It’s the white one.o_O
    After consulting me Google, Menu 4 says premier24 v8.33
    I can get the engineer code from the alarm monitoring people. They also provide phone support so they could talk me through it if I know exactly what I am after.
    Do I understand correctly that you want me to configure the alarm to forward that PIR event when it’s in disarmed state (currently ignored) as some sort of trigger out and I can use that as a control for my relay? So i will need to configure that and then connect some wire into some sort of “trigger out” area of the alarm then test that it generates 12v DC when PIR gets triggered?
  5. sparky steve

    sparky steve Screwfix Select

    Select the Output, then define it as a Zone Mimic. the output will activate when the zone is triggered. Under attributes, you can chose a PULSE 1, 2 or 3 and those have defined durations which you can tweak - so 5 seconds, 10, 2 minutes.
    You can simply program a zone as "Not Used", and the "Zone Mimic functions will still work, but not cause any alarms on the system.
    The output will activate for as long as the detector does, or again, you can add the pulse attribute if necessary to add extra time.
    However, remember once the pulse timer has started, it cannot be stopped until it expires.
    Last edited: Jan 7, 2022
    FlyByNight likes this.
  6. FlyByNight

    FlyByNight Screwfix Select

    Saved me typing it! @MinionBob get a copy (online) for the Texecom Premier (not Elite) and that will explain more.
  7. MinionBob

    MinionBob New Member

    CAE5ABC4-0E88-4A40-9FB7-AA4CBA56C84B.jpeg EB9D3589-B169-4004-98F6-54CDF80DC3A6.jpeg

    So it’s number 8 on PCB picture and then wire it together with +12v that is from number 10? That will go into relay.
    Then configure it to mimic that zone and minimal trigger pulse should be enough to get it going - I assume it will keep retriggering is someone loiters in the corridor so the screen will stay on.
    Is it ok to use a couple of pairs of network cable - a pair on +12v and a pair on Output.
  8. FlyByNight

    FlyByNight Screwfix Select

    That is basically it.

    You need, as you say to define the ouput as ZONE MIMIC and define which Zone - covered towards the end of the manual. Experiment with pulse lengths until happy.
  9. MinionBob

    MinionBob New Member

    Thank you very much.

    Lastly, in terms of relay wiring: the load side is simple enough but the switch side is tricky for an amateur. Does it require permanent 12vdc supply and my 12v alarm output can only be used as a signal or can I use some bridging to use my output both for signal and power?
  10. MinionBob

    MinionBob New Member

    Did as discussed. Mimic zone to the output. Connected output and 12v dc aux power using network cable and wired a relay into a little donor extension lead. Now have a small 220v extension lead that turns on when someone walks into the hallway.
    Haven’t tried a screen yet but it clicks instantly when the PiR lights up (Pir takes a good second though) and stays on when I retrigger PIR. Then clicks off after 40sec when all is quiet.
    I suspect screen wake up will be the largest contributor to latency but hoping it will still be ok. Better than lighting screen for the whole day on simple timer.
    FlyByNight likes this.
  11. FlyByNight

    FlyByNight Screwfix Select

    Thanks for the update telling us that it works ...
  12. MinionBob

    MinionBob New Member

    for completeness I was wrong about the #8 on pcb picture. The “panel outputs” in the menu or the ones marked with #16. But mine had first few used to dial out to monitoring centre so I wired one of the empty ones.

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