Hey I was exploring the possibility of trying to make a do it yourself backup siren. How do these sirens usually work?

I was thinking $10 regular siren, and a relay hooked up in such a way that the normally closed contacts would be connected to a battery and the siren + side, this way when power is cut, the relay would unlatch and and power would be fed from the battery to the "backup" siren.

this method requires a relay to be constantly latched...and I was looking for a better/proper way to do it. Any input on this, or a similar system to battery backup my alarm brain would be great!

-Rage

P.S - oh yea, i was going to use a regular 12 volt 7ah sealed ups battery

 

If power was cut what suppiles power to the siren?
You would need an additional battery hidden somewhere that would be able to supply power to the extra siren. Your idea would work it just wouldn't be very efficient. Transistors could do the job better and use less power to run. That would be one seriously overworked relay.

I am curious as to why you would want to do it this way when they make back up sirens and back up batteries for the alarm. They are not that expensive, they will be more reliable and less problematic.

Good luck

 

The battery in my P.S supplies the power (notice no edit!!)

yea your right, i was just thinking of doing it myself and hopefully be able to also supply a backup for the brain and the battery at the same time. I'll look into transistors. Is the backup battery your talking about for the alarm and the brain an Addon or do you have to have a special backup battery siren and a module for backup battery on alarm?

-Rage

 

I thought you were going to use the ups battery for just the alarm.

The back up siren I use is the clifford siren, $40. The advantage of having the battery inside the siren is someone can't just yank or cut the power wires going to the siren. A friend of mine has had this happen a couple times.

The backup setup I use for the alarm is the dei backup battery $20. Keep the module toss the battery that comes with it, and replace it with a bigger battery.