Hi,
I have the Yale SR-1100i Wireless Home Alarm system which only has an internal siren. I want to add an external siren with LED’s but they’re no longer available. I hoped to be able to connect a relay, which would then power my setup, by connecting it to the sounder inside the box but the voltage/current, I believe, is digital. I can’t find out what type of sounder it is but think it may be a SMD piezo. I’ve tried a LED isolated type relay but again no joy. I’m thinking that perhaps some kind of voltage detector could be used to make the relay work or failing that maybe there might be strong enough magnetic fields to use a reed switch.
Has anyone ever tried to get this kind of setup working?
Regards,
Peter

 

Would really need the system circuit diagram to start from which they don't include in their manual.

 

An oscilloscope at the piezo sounder will show if its activation is AC or DC and its voltage. Then an opamp circuit driving a Mosfet used as a relay can activate your external siren with LEDs.

 

I am in the middle of a similar project. My hearing is bad. I can not hear any frequencies above about 2KHz. This is a concern because all the smoke detectors in my house give a tone of about 3.3KHZ. I have built a small amplifier which has an electret microphone and a narrow band-pass filter. The output goes to a Bluetooth transmitter. It will be located at the top of the stairs, fairly close to the smoke detector there. The audio signal from the receiver will activate an 800 Hz sound transducer. This will be located on my bedside table. Both units will be powered from wall-warts with 9V battery backup in case of power failure.
This is not exactly what you are proposing to build, but it may give you some more Ideas on how to do it.

 

This is a photo of the inside of the siren unit. Does this match your alarm?
Read everything you see on sounder.
Should be possible to connect directly across the sounder to access a voltage to drive a mosfet or relay circuit.

 

Thank you all, lots of helpful comments. Yes, I believe that’s how the sounder looks, I’ll check later today as I’m out for a few hours.
Yes, I’ve tried the optocoupler relay.
I’ll try to get some readings so we know more about what is required.
Peter

 

I am in the middle of a similar project. My hearing is bad. I can not hear any frequencies above about 2KHz. This is a concern because all the smoke detectors in my house give a tone of about 3.3KHZ. I have built a small amplifier which has an electret microphone and a narrow band-pass filter. The output goes to a Bluetooth transmitter. It will be located at the top of the stairs, fairly close to the smoke detector there. The audio signal from the receiver will activate an 800 Hz sound transducer. This will be located on my bedside table. Both units will be powered from wall-warts with 9V battery backup in case of power failure.
This is not exactly what you are proposing to build, but it may give you some more Ideas on how to do it.

My hearing is also bad, but is normal for my age so I got Phonak hearing aids 8 years ago when I turned 69. The Canadian government helped to pay for them. My hearing is tested and the hearing aids are re-programmed each year.
They allow me to hear almost everything but have a switch to select noise reduction and compression of too loud sounds or perfectly linear for music. They can send and receive BlueTooth from my phone.
Of course the hearing aids communicate settings with each other wirelessly. The first ones lasted 6 years and used cheap little button disposable batteries but the 2nd ones are rechargeable.
Here is a graph for normal-with-age hearing loss:

 

My hearing is also bad, but is normal for my age so I got Phonak hearing aids 8 years ago when I turned 69. The Canadian government helped to pay for them. My hearing is tested and the hearing aids are re-programmed each year.

I have Bernafon hearing aids. I too switched to rechargeable ones a couple of years ago and get them reprogrammed every two years. The problem with the smoke detectors is that I don't use the hearing aids when I am sleeping, so I would never hear an alarm.

 

I have Bernafon hearing aids. I too switched to rechargeable ones a couple of years ago and get them reprogrammed every two years. The problem with the smoke detectors is that I don't use the hearing aids when I am sleeping, so I would never hear an alarm.

My wife and dog bark loudly each time I test the smoke detectors.

 

Would really need the system circuit diagram to start from which they don't include in their manual.

Thank you Sam but you are correct, no circuits available. I have now had a reading of 29v AC on the siren so I'm guessing I can use a couple of diodes or perhaps a four diode bridge to get dc to my relay.

 

This is a photo of the inside of the siren unit. Does this match your alarm?
Read everything you see on sounder.
Should be possible to connect directly across the sounder to access a voltage to drive a mosfet or relay circuit.
View attachment 299583

Yes, that's how it looks. I have now had a reading of 29v AC on the siren so I'm guessing I can use a couple of diodes or perhaps a four diode bridge to get dc to my relay.

 

An oscilloscope at the piezo sounder will show if its activation is AC or DC and its voltage. Then an opamp circuit driving a Mosfet used as a relay can activate your external siren with LEDs.

Thank you but I just wan a simple connection to a relay. I have now had a reading of 29v AC on the siren so I'm guessing I can use a couple of diodes or perhaps a four diode bridge to get dc to my relay.

 

Thank you but I just wan a simple connection to a relay.

Do you have a link to that relay module mentioned in post#1?

 

Do you have a link to that relay module mentioned in post#1?

It's a Relay Switch Module with Optocoupler, on eBay here: https://www.ebay.co.uk/itm/17582864...lw6q7AzqNa6sRoLVzLxoCH/Fk=|tkp:Bk9SR9C42Ou2Yg

 

What is the supply voltage for the relay module?

 

What is the supply voltage for the relay module?

I have the 5v version

 

And a 5 volt supply for that module?

 

And a 5 volt supply for that module?

Well I think that the 29 v AC will produce something like 35-40v DC so I’ll probably use a normal 12v relay with a v drop resistor. Am I on the right track?

 

Well I think that the 29 v AC will produce something like 35-40v DC so I’ll probably use a normal 12v relay with a v drop resistor. Am I on the right track?

I don't think you can power the whole module from the sounder but use that voltage source as a trigger for the relay module.
What is the battery voltage in the siren unit?

 

I don't think you can power the whole module from the sounder but use that voltage source as a trigger for the relay module.
What is the battery voltage in the siren unit?

The alarm unit is powered by 4x 1.5v D sized batteries