Need a part - TTL triggered 12v relay and timer for siren

[Razer]

Hello all, been searching but thought this might save time if someone already knew the correct solution.

I need to trigger a siren and light with my TTL alarm outputs. I have a power outlet type of device I can trigger with my TTL alarm outputs no problem but the downside is if a door is opened and the alarm off my DVR triggers the alarm it will not shut it back off. If someone pulls a door open and leaves it that way the siren will go off until someone kills power or the alarm trigger is reset by shutting the door. That will greatly annoy the neighbors, so I want to have a timer that it will only go off for say one minute.

Anyone know of something that will work well? I have found good timers, and I could just add a timer to the DLI IoT relay I have now, but that add complexity. I would prefer one board to do it all as I have to install 60 of these.

 

[drew91101]

Get an arduino and a relay board. Its a very simple code to write and you will have complete control over how long the relays are closed for, what conditions, ext. You could do it all for under $30

 

[Fastb]

A simple 555 one shot circuit could do it.
http://555-timer-circuits.uk/operation/one-shot2.html
Some calculations will be needed, to program the alarm-on time.

A solderless breadboard could be used to avoid soldering and making a circuit board.

No programming. Cost <$10.
The "arduino & relay board" might be less time consuming to build the 60 units.

 

[tangent]

Here's a simple board that combines a relay and timer and is targeted at security applications:
ELK-960 Delay Timer Module
see bell cut-off example

When you say "TTL alarm output" I'll assume you're talking about the alarm output from a camera or nvr. Feeding that directly into a relay and siren doesn't work the greatest because there isn't a good way to disarm the alarm.

You say you need 60 of these. Are these for a single facility? Many facilities? How do you plan to disarm it so the siren doesn't go off? Do you need an entry delay to allow time to disarm like a traditional alarm? More details = Better advice.

For something basic but more capable the ELK-MM220 Magic Module Programmable Controller, 2 input, 2 output comes to mind

 

[tangent]

There's also the direct from china route just don't go buying 60 all at once as documentation is limited.
LED Display Digital Delay Timer High Performance Timer Relay Module Automation Control Relay Switch Module 3V/3.7V/4.5V/5V/6V-in Relays from Home Improvement on Aliexpress.com | Alibaba Group


The Altronix 6030 is another option and is slightly cheaper
Altronix Products: 6030 - Cut-off / Delay Timer 6/12VDC

 

[nayr]

Seco-Larm SA-025Q Enforcer Multi-Purpose Programmable Timer Module - Wall Timer Switches - Amazon.com

there's a mini version too for a couple more bux

 

[drew91101]

I'm still sticking with arduino. You can get an off brand nano and single relay board for $11 (and probably cheaper if you get 60). Write the program once and upload it to all 60. You can program entry/exit delays, timer settings, whatever you can think of.

 

[tangent]

Seco-Larm SA-025Q Enforcer Multi-Purpose Programmable Timer Module - Wall Timer Switches - Amazon.com

there's a mini version too for a couple more bux

The amazon listing doesn't mention it, but the Seco-Larm SA025Q is supposed to come with a case. Did yours come with one?
Multi-Purpose Programmable Timer with Protective Case

The ardunio route works too. One feature these timers lack that a traditional alarm would have is swinger shutdown, you could implement something like that on an ardunio.

 

[nayr]

the case is optional, the one off amazon did not come with one.. I'm using it to extend the momentary tap of my doorbell sensor into a long enough trigger the NVR and my automation system will reliably trigger without needing debouncing either.. software debouncing; well kinda sux

 

[Razer]

Just an update so people can know what I ended up going with. I am sitting up alarms at 60 separate locations, the alarm is triggered off a standard door contact switch going to an alarm input on my NVR. I then have a schedule set up for this alarm to trigger an alarm output every single time during my desired hours. During the time people need access it will do nothing, off hours are off hours though. No one should ever be on site in this specific room during off hours so I have it set to trigger every time the door is opened so no delays or activation keypads and the like needed at all.

I am using the IoT relay from digital loggers which will turn on power outlets when the TTL alarm output from my NVR goes off. Then the ELK960 timer is then energized and powers the alarm strobe and siren for whatever time you set it to. Then the ELK will shut down the power to the siren and it will stay off until the alarm is cleared. Alarm clears and the outlet is shut down, thus resetting the whole thing and it is good to go until next use. I have the ELK960 set to "one shot" for my uses.

I wanted the timer so as to not annoy the neighbors if it went off for 20-30 minutes non stop. I also have the ability to have my alarm trigger for a minimum amount of time on my NVR, so if someone opens the door and the alarm goes off and they shut it again it will not reset the alarm until my minimum time has passed. So open the door and run away shutting door, it still goes off for set amount of time. Smash the door and ruin it or leave it open then alarm will go off until timer disables siren. Should work fine.

Only possible flaw is if door is say flapping open and shut in the wind, then the alarm will be getting reset and go back off from time to time but authorities will be there eventually so not too concerned about that. Also have 24 hour a day live monitored email alerts tied all alarms so a person will be responding to these in real time too, alarm is just to encourage they leave even faster.

 

[tangent]

I am using the IoT relay from digital loggers which will turn on power outlets when the TTL alarm output from my NVR goes off. Then the ELK960 timer is then energized and powers the alarm strobe and siren for whatever time you set it to. Then the ELK will shut down the power to the siren and it will stay off until the alarm is cleared. Alarm clears and the outlet is shut down, thus resetting the whole thing and it is good to go until next use. I have the ELK960 set to "one shot" for my uses.

You really don't need the "IoT relay" at all. Just wire the NVR alarm out directly to the timer module which has a built in relay. Wire a power supply for the timer board and siren up to the timer and your good to go. TTL generally means 5v but can mean different things to different people, not sure it's relevant here. I thought most NVR outputs were open drain they just can't sink much current ~20mA, but I could be wrong.

Only possible flaw is if door is say flapping open and shut in the wind, then the alarm will be getting reset and go back off from time to time but authorities will be there eventually so not too concerned about that. Also have 24 hour a day live monitored email alerts tied all alarms so a person will be responding to these in real time too, alarm is just to encourage they leave even faster.

That would be the swinger shutdown I mentioned earlier. Depending on the type of door this may or may not be big a concern. For overhead doors that can move a little in the wind, you can put 2 contacts on them wired in parallel instead of series so both have to break to trip the alarm. If it became a nuisance, you could always go the arduino route.