How Electronic Siren Module work?

[me_guitarist]

siren module

Is there anybody can tell how the electronic siren module builded? The one used on security/fire alarm systems. And how they control the tones?

 

[VVV]

Basically you need an oscillator, whose frequecy is controllable. That is what changes the tone, the frequency of the signal. Then you need a powerful amplifier and that is the siren. sometimes, they mix two signals, to obtain different tones.

 

[me_guitarist]

can we manufacture it ourself?

 

[IanP]

It is not difficult to build a siren .. see picture below ..
Here are some other siren designs: http://www.discovercircuits.com/S/siren.htm

Regards,
IanP

 

[me_guitarist]

how about on 24v dc with min. 4 tones selection?

 

[Jepeto]

You can use digital counter with low pass filter or to sum 2 or more sine waves to generate more then 2 tones
I guess that in commercial security system the microprocessor used to generate the tones
For 24VDC you will need voltage regulator for COMS levels the siren driver can works with 24V

 

[me_guitarist]

how to control tones with DIP switch selection?

 

[VVV]

Use the DIP switches to switch in and out of the circuit some capacitors in parallel with the timing caps, to change the frequency. Alternatively, you can use the switches to add resistance in parallel or in series with the timing resistors.
In the end, what matters is that you change the frequency.

 

[me_guitarist]

to control/select the tones

 

[roykyn]

try http://www.discovercircuits.com/list.htm