Loud alarm.

[Allan]

Many years ago I fitted some alarms in a factory. They had a warning which said "could cause injury if fitted within 15 feet people". I can't remember how many decibels they were. They were 110v. I am now looking for a 12v version but can't find one anywhere. Any ideas where I could find something like this?
Allan

 

[awol]

Plenty 12v, 120db @ 1m, Piezo noise makers available. Just Google "12v burglar siren"

 

[Allan]

Thank-you, do you know if 120db is enough to cause damage to the hearing?
Allan

 

[awol]

As a rough guide, any sound over 85dB will cause damage but it takes a while - over 140dB you can be reasonably sure of instant damage and pain. Remember distance is a factor with a square law applying - 2 x the distance = 1/4 the sound level.
What are you doing - designing a sonic blaster?

 

[webcraft]

Thank-you, do you know if 120db is enough to cause damage to the hearing?
Allan

Whose hearing are you wanting to damage?

- W

 

[Allan]

I don't want to damage anyones hearing. I am planning to fit an alarm to my boat. If some scrote breaks into my the boat and the internally fitted siren, designed to warn others of the break-in, does permanent damage, that will be unfortunate.
Allan

 

[BlueLancer]

Fitted a Master Blaster siren to my workshop 180 Decibels.,240v but can be fitted to work with a 12v alarm, you just need the correct switch. Mine is inside my metal clad workshop, I full well anticipate bleeding ears for anybody who enters uninvited.

 

[pvb]

Fitted a Master Blaster siren to my workshop 180 Decibels.,240v but can be fitted to work with a 12v alarm, you just need the correct switch. Mine is inside my metal clad workshop, I full well anticipate bleeding ears for anybody who enters uninvited.

The Master Blaster is mains powered, so it wouldn't work on 12v. And, although loud, it's only rated at 127dB.

 

[BlueLancer]

I stand corrected as to the decibels sure sounds like 180 in a tin shed .I did mention it was 240V