Use sound bomb and old mains unit to make a loud door bell?

[Silvan]

Hello,

I want to make loud door bell. I already have a push button outside the house and wires leading inside the house.

I was wondering if I could use a sound bomb an an old 12v mains unit?

Would the sound bomb make its loud noise when the circuit was completed by somebody pressing the door bell outside and stop making a noise when the person removed their finger from the door bell outside the house? Or do these sound bombs have some complicated electronics inside them that means they have to receive some kind of signal to switch the noise off?

By sound bomb I mean something like:
http://www.ebay.co.uk/itm/Twin-Piez...8518?pt=UK_Burglar_Alarms&hash=item2324f087b6

Many thanks for reading.

 

[footprints]

Do you really want to develop tinnitus? It ain‘t fun I can tell you!

A sound bomb is designed to be so painful on the ears that an intruder cannot bear to stay in the house. Long term it can cause damage to the ears.

I would look again, lots of aids for the hard of hearing, with loud bells out there that could be suitable for your purpose.

 

[ekmdgrf]

That's probably a better use for a sound bomb. I purchased one to test and I think it fails somewhat in its claim to drive people out of the house. It's highly directional and unless you're directly in the line of fire it's only barely noticeable. You can just stick a 12V power source and it will make noise, so to answer your question: yes. You may want to stick a capacitor or 555 timer into the mix to give a little more duration if the user only presses the door bell momentarily.

As for replacing the sound bomb, I've found the Klaxon MasterBlaster put out some serious, serious sound and although ear damaging, it's not really that painful. I have found that when the impeller spins down that it does generate a seriously unpleasant sound at one point so I might put some PWM circuitry in there and see what happens. I've also had a go at generating some unpleasant sounds with Audacity. 2600Hz with some harmonics seemed to work quite well at nearly making the YL loose the contents of her stomach.

 

[Silvan]

Thank you folks, might give it a go, can always muffle it a bit if i need to, or maybe will look for loud bell.

 

[Ricardus]

I've also had a go at generating some unpleasant sounds with Audacity. 2600Hz with some harmonics seemed to work quite well at nearly making the YL loose the contents of her stomach.

Have you been able to test that through walls?

Say - purely hypothetically of course - with a 15" powered home cinema sub and an annoying neighbour?

 

[Europlex]

Find an old 6", 12vDC Alarm bell, different noise, but WILL do the job.

Fleabay is good.

 

[ekmdgrf]

http://en.wikipedia.org/wiki/Chrysler_air_raid_siren

Might be a little delay after someone rings the bell but it should do the job

 

[RF Lighting]

The siren could be heard from a distance of 20 to 25 miles (32 to 40 km) away and had an output of 138 dBC

 

[bernardgreen]

You could consider the Chance Diaphone system

http://lighthousememories.ca/wp-content/uploads/2012/04/Chance_Diaphone_Manual.pdf

One of the larger ones is reported as having a range of over 40 miles

Description: Newspaper cutting from The Daily Herald titled 'World's Loudest Fog-Horn: New Instrument with a Range of 40 Miles'. Newspaper cutting from The Daily News titled 'The 40-Mile Bellow: New Fog-Horn Frightens the Cows'. Newspaper cutting from The Manchester Guardian titled 'Fog-Horn with Forty Mile Radius Adopted by Trinity House.' All refer to the construction of a fog-horn called the diaphone at Chance Brothers which will be installed at lighthouses.(26th October 1926)

It has a soft rumbling sound, not a vicious shrill scream.

 

[footprints]

A sound that cannot be missed.
I could sell you a recording of the wife telling me to get off the computer and come down for dinner, or my grandson when the world is not as he would like it!

 

[Ricardus]

The siren could be heard from a distance of 20 to 25 miles (32 to 40 km) away and had an output of 138 dBC

And could turn rain to fog.

 

[Silvan]

Well I finally got round to trying this.

Yes it is too loud, maybe not a great idea after all.

But also a technical problem which I don't understand. The power source I have is an old mains unit rated 6v 500mA (it is a heavy one so I think it has a transformer inside). It works fine on the bench testing - by that I mean that the sound bomb goes off when the sound bomb is connected to the mains unit.

But once it is wired it up to the doorbell push button the sound bomb gives a continuous alarm even when the doorbell is not being pressed. When the doorbell is pressed the sound bomb gets louder. The distance to the doorbell is about 10 meters, the wire in use is pretty flimsy, it was used for hi-fi speakers originally.

 

[ekmdgrf]

Is the door bell push not breaking the circuit completely when it's not depressed? Disconnect the switch and see if you have the same problem.

Did someone zip tie the bell wire to a mains cable?

 

[Silvan]

The bell-push and cable work okay with a more conventional bell which I have in use already, so would I be right to assume that the bell-push must be breaking the circuit properly?

Not sure what the second question means, the cable from the bell-push to the actual ringer is not running closely alongside a mains cable, it is outside the house mostly.

 

[ekmdgrf]

A conventional bell often uses a magnetic actuator. If there's a small amount of current flowing when the button is released, it wouldn't be enough to sound the bell. With a piezo-sounder like in the Sound Bomb, a small current may be enough for it to make a slight noise. That's all speculation. I'm no expert in the deep, dark physics of electron flow