Possible depending on the relay current. Another option is a CPC1002N SSR. It can handle 700ma.

 

Is it possible to add a detection system for when the detector itself fails or loses power? If these were to happen, the low voltage the detector outputs when it's in normal mode would be completely cut off. A circuit that detects the absence of that low voltage and powers the relay would make it much more secure.

 

Not sure what you mean. If the detector drops out so does the relay. If another circuit detects the absence of the low voltage and powers the relay why would you need the detector to begin with?

 

The relay is connected to the security system in a normaly closed config and is not active normaly. It activates when the detector senses smoke thus cutting the circuit on the security system's side sounding the siren. The flaw with it right now is that if the detector fails the system won't see that and not react to smoke and you can't know that unless you regularly test the detector. I want it to also activate the relay when the detector fails so i would know to replace the detector.

 

and you can't know that unless you regularly test the detector.

That is the standard procedure for knowing the detectors are working properly.
The only thing I see on the detector that might work is monitoring the function of the Green LED.
It says the LED flashes when operation is normal.
How often does it flash exactly?

 

Yes, the LEDs flash subtle green every 10 to 20 seconds and that would be an indication of the detector's health. However my concern is that it fails when I'm away from the location. There are times I'm away for a few days and can't physically check the detector.

 

Exactly how often does it flash?

 

Strange. It blinks every 3 seconds. Before there was a much larger gap between blinks.

 

Strange. It blinks every 3 seconds. Before there was a much larger gap between blinks.

OK but it blinks at least every 30 seconds correct?

 

it blinks at least every 30 seconds

Yes, correct.

 

I have a simple timer circuit that can be connected to the existing circuit to activate the relay if the green LED fails to flash at least say in 30 seconds. It involves mounting a LDR or Light Dependent Resistor on the detector.
The circuit is shown inside the gray box.

 

Another version if you can tap directly off the Green LED.

 

Even with a min gain of 130, the C945 (Q1) probably will not be firmly saturated with only 1 mA of base current. Consider reducing the value of R2.

ak

 

That part of the circuit is already built and working.
See post #67