Status LED as Deterrent

[Frank Hagan]

Newbie here, and I've tried search and didn't see this addressed:

I want to figure out a way to have an LED at each entry location that shows there is an alarm system. I'm hoping for a deterrent effect so they don't destroy the door before the alarm goes off.

Background:
I have a NX-4FP system I'll be installing at our desert cabin. It is remote and without phone service, but has full-time neighbors within the area who can respond to an alarm. I plan on using the motion detector in the main cabin room and sensors on the windows and two doors. I am adding a strobe and additional siren on the roof as well.

There really isn't much in the cabin for people to steal, some small appliances and hand tools. Last week, someone chiseled away at the door, kicked it in, and stole about $50 worth of stuff. The problem is the damage they do when they destroy a door, and vandalism they sometimes do to the structure itself. In this case, its about $400 in doors and materials to repair the damage.

The NX-4 panel has two AUX outputs that can be programmed to output when the system is armed. I will have one to drive the strobe (180ma) and additional siren. The other I'm thinking can be used for the LEDs at each window and door (total of 9 LEDs) I suspect its a 12v AC output, right? Looking at LEDs, I see some that are 12V DC, but require a diode rectifier to work on AC power. My problem is that I have no idea how to wire this up, or if there's an easier way.

Would it be easier to just use a wall wart that outputs 12v DC and do a home run wiring all the LEDs in series? How would you do this?

 

[AnthonyZ]

This will get you started...

 

[Frank Hagan]

Thanks, that's exactly what I needed! I'll use a 19v DC power supply I have left over from a laptop and buy the 9 leds and 1/4 w 56 ohm resistor the calculator advised!

 

[SteveQ]

If you don't want to run wires to the LEDs, you could use this http://www.radioshack.com/product/index.js...oductId=2062571

It has the added advantage of working when the power is out.

Steve Q

 

[pipeman]

That calculator puts all nine LEDs plus the resistor in series. In my view thats not the best way to do it. If one LED, the resistor or any part of the wiring fails, you lose all of the LEDs and have to troubleshoot the entire loop.
I would prefer individual home runs, all parallel wired with individual 1k resistors.
The current supplied by your wall wart will still be less than 200ma.

 

[Frank Hagan]

That might be a better idea; I had only found more expensive ones. I would imagine 2 AA batteries would keep the unit flashing for a long time (we are out there every few months).

 

[signal15]

I wonder how much of a deterrent a blinky red light will be in an extremely remote location. If I were a intent on breaking into a place and robbing or trashing it, and I knew the cops were a long ways away, I probably wouldn't think twice about an alarm system.

The thing that would get me thinking though would be a voice alert triggered by motion that told me my face had just been recorded by video surveillance and sent to a remote location via the internet. Of course, I probably put too much thought into what I would do if I were a criminal.

 

[Frank Hagan]

Not really "extremely remote"; there are neighbors who live there full time less than 1/8 mile away, with no visual obstructions between them and us. They can easily see a car in our drive, and anyone walking around. The neighbor who discovered the break in noticed that our door looked funny; he got the binoculars out and saw it had been kicked in.

I'm going to alarm the new "security" screen doors we put on so that they will trigger the alarm, and will probably put sensors on the locked shutters we drop down over the windows later (I have to figure out how to put sensors on them that won't trip when the wind rattles them a bit). I'll put alarm stickers around too. I had thought about adding a piezo buzzer in series with a motion detector light just to warn them off, but its the desert and I've heard the motion detectors have problems in bright sunshine.