Need some help with amplifying a sound

[large_ghostman]

I have four brooders with young quail in, there are almost fully feathered, but still very much need heat, these quail are the miniature Chinese painted type, because of space limit's, they are currently housed in groups in small brooders. Each brooder at the moment has a 60W bulb inside a wire mesh cage i make.
I didn't get chance this morning before school to go feed and check them, as i knew i would be home lunchtime today (now). I went to check them and one brooder has a bulb that has gone, i use good quality bulbs but they never last long!
Unfortunately all 40 young quail are dead in that brooder, i have worked so hard in hatching them and raising them this far, i am in tears and feel really bad and upset.
ANYWAY
TODAY i need to make an alarm system, so if it happens at night again (its always at night!) i can run down and change the bulb, i cant put 2 bulbs inside there isnt room. I can make a simple LDR ladder connected to a micro no problem, i can make simple sirens and bleep and tones with the pic, no problem.
The bit i need help with tho, is they are not loud enough as is. As i need/really want to make this now, i have to use what is here.
i am not asking for circuits or stuff like that as i can go look for that on net, or maybe design myself. But i do need to know what kind of amplifier i need to make so i can connect the pic sound out put to it and have it drive a speaker loud.
I have some small pc speaker's to hand (speakers not those buzzer things), they are 8 ohms, i have some other speakers that are in a cupboard somewhere that i think are 16 ohms??? not sure on this, but from memory i know they are around 3 times larger in size than the pc ones and higher in ohms, 16 Ohm's just rings a memory, but might not be right, i will try and get them down in a bit.
So what kind of amplifier configuration do i need? and i forgot to add the brooders are in a room below mum and dad's bedroom, i tried the pic and speaker sound, and it cant be heard in there room as it is now.
In a ideal world i would like 120 db or something as loud as a car alarm or smoke detector. But i will settle for any gain, the sound dose not have to be pretty, distortion and noise dose not matter. What matters is its loud! so as a figure of the top of my head, i would like to aim for say 80 db, but obviously will go with whatever i can get.
So what kind of amplifier do i need to build for this? and what components do i need?
And honestly i dont expect anyone to do the work for me, but i am not sure what kind of circuit i should be building, i know i need an amplifier but what kind sort of thing, this will get me on my way at least
THANK YOU very much! sorry to ask for this, but i dont want any more birds to die

 

[JimB]

My first thoughts are to suggest something like an LM386 amplifier IC. Not the loudest thing on the planet, but able to make a noisy noise to attract attention.

As I am typing, it occurs to me that you may have something in your "junk pile". A redundant radio or "hifi", use the audio amp from something like that.

JimB

PS, sorry about your birds.

 

[alec_t]

Shame about the birds.
Really loud alarm beepers, such as in the smoke detector, are available cheaply and could be triggered by a PIC via a transistor. Cheaper/simpler than an amp?
Just don't hack the beeper out of the smoke detector; your Dad would be unhappy!

 

[dr pepper]

Tda 2030 is a good amp ic with built in heatsink tab and it'll work from a 12v battery, and make a lot of noise, google for a datasheet.
Another simple thing is use a piezo cell, switch the ground side using a fet and place a 470uH or so inductor across the piezo, you'll also need a current limiting resistor in series with the + supply, say 22 ohm, the fet needs to be a high voltage to stand the high voltage inpulses from the choke.

 

[large_ghostman]

I need to do it today tho even if its a temporary thing until i can get parts here. i might have some obsolete amplifier chips, i had forgotten about i will go look.

 

[dr pepper]

If its a rush pinch the speakers of yer old mans computer.

 

[large_ghostman]

ok i thought i had a amp chip, but its not what i thought it was, It is a AD 815AVR, could this be used?
or can i use say ordinary opamp and fets in some configuration? i have inductors but no buzzer thing. Will be at least 4 days before i could get parts here, so having to make do with whatever i can find here. Must be something i can build with all this junk!

 

[large_ghostman]

no external speakers and i have the internal one in my hand

 

[large_ghostman]

datasheet is here https://pdf1.alldatasheet.com/datasheet-pdf/view/48416/AD/AD815AVR.html

 

[Externet]

Aiming this post towards the heat source instead of audio... What happened to those young should not repeat. May happen again when there is nobody home to act from the alarm. And the more complex you do it with a microcontroller, the higher the risk of something failing.
You should also think of a backup heat source from car batteries to take over if a long power outage happens.

Replace the 60W at 120V heating bulbs with ~ 150W at 230V , still fed by 120V instead; or, ~150W at 120V fed with a diode in series. They should last about 20 years.

 

[MikeMl]

Roman just posted this on the "other" forum

 

[large_ghostman]

we run from 230V, power back up is under control, a bulb going isnt. I am having to replace bulbs every couple of weeks, they are good Osram one's. I dont know why they blow so often but they do, this is why i am building the other heater with wound elements. But until i can get that sorted i need an alarm system sorted for a couple of days or so. Is it really not possible to knock something up with a few transistors or fets and opamps?
Thanks Mike i will get some ordered for the future

 

[large_ghostman]

ok found 2 that are not great but might get me out of a hole.

I except they wont be anywhere near the volume i hoped for, but worth a try. I will try and sim it first, see if it's worth building

 

[large_ghostman]

If the postman turns up today, i might have the other stuff i am waiting for, then i can make one of the new heater's, and do away with the bulbs at last.

 

[Reloadron]

Try a Google of Sonalert or Mallory Sonalert. These come in a large variety of flavors and audio levels. They scream and I have used assorted flavors in various alarm circuits. I know Mouser distributes them. Also as suggested open up a smoke detector, they scream pretty loud too.

Ron

 

[large_ghostman]

Smoke detector was my first thought, but dont have any not being used, only place i can think of picking one up from will be shut by the time mum can drive me there. I have no idea why we get through the bulbs so quick, we use CFC's for lighting and they are fine, well i say fine but we have blown 2 new ones in 4 month's, we do have alot of power cuts, and probably alot of spikes (i might try 10x probe on scope and set trigger over 260V single shot see what i get), although i can only fit one bulb per box maybe wire a smaller one in series outside the box? say 20W? would that help damp spikes?

 

[large_ghostman]

I know its all a bit panic, but i am really upset about them. They are so hard to get to the stage i had them at, i worked really hard at it.
The lager Texas and jap quail are nowhere near that sensitive to low temps! but these guy's are tiny

 

[large_ghostman]

problem solved! unconventional but will do until i can get the new system up and running

 

[alec_t]

What was your solution?

 

[large_ghostman]

We had a old velleman thermostat kit, i took the thermistor out and added a LDR, so when light goes out, the relay on the board triggers, this is now wired to mums radio turned up full blast . It will do for a couple of days while i work on the whole thing, and get the new heaters in