Self-activating sonic fire extinguisher

Hi, I'm trying to create a self activating sonic fire extinguisher (it uses sound waves to displace oxygen and "suffocate" the fire) using an LM35 Temperature sensor, an arduino uno, and some type of amplifier, as well as a subwoofer. How would I go about doing that? Also how would I program the arduino to turn on the amp once the temperature sensor sensed a certain temperature?

A practical device, or a science demonstration?

It's for science fair

Separate the problem into separate, manageable parts. Certainly you will find it easy to do the temperature threshold sensing part because sketches for that are all over the web. A lot of sub-woofers have built in amplifiers so that part might be easy to cover.

But how would I combine them once I have done this?

JonasQ: But how would I combine them once I have done this?

Come back and post your efforts when they are done, and we can help. It's impossible to work with hypothetical code.

JonasQ: But how would I combine them once I have done this?

Hi, Welcome to the forum. Please read the first post in any forum entitled how to use this forum. http://forum.arduino.cc/index.php/topic,148850.0.html Can you please tell us your electronics, programming, Arduino, hardware experience? Get the first two stages completed first.

Learn and code the LM35. Learn and code how to switch an OUTPUT ON and OFF.

You will probably by then have an idea how to combine them.

google arduino uno lm35 You will find many examples to help you.

We will not write you code for you, but will help you edit it as you go. So go and google and give it your best shot, then come back and ask us any questions or advice if you need help.

Thanks.. Tom.. :)

JonasQ: But how would I combine them once I have done this?

Nobody can know until you get to that point. That's the whole point of getting the little pieces to work first. Once you get them all working then you can look at them and see how they might fit together. But right now you don't even have the little pieces to look at so you can't imagine how they might go together.

Out of curiousity: do you have any reference on how this sonic fire extinguisher could even work? I for one don't see how sound waves can take away the oxygen from a fire to the extent that the fire can't burn any more.

Yes, watch this video https://www.youtube.com/watch?v=hkUv5gCA-1w

TomGeorge: Hi, Welcome to the forum. Please read the first post in any forum entitled how to use this forum. http://forum.arduino.cc/index.php/topic,148850.0.html Can you please tell us your electronics, programming, Arduino, hardware experience? Get the first two stages completed first.

Learn and code the LM35. Learn and code how to switch an OUTPUT ON and OFF.

You will probably by then have an idea how to combine them.

google arduino uno lm35 You will find many examples to help you.

We will not write you code for you, but will help you edit it as you go. So go and google and give it your best shot, then come back and ask us any questions or advice if you need help.

Thanks.. Tom.. :)

Thanks Tom

I have a basic understanding of programming and electronics, but I know very little of arduino. I will begin programming now, and will let you know of any further problems

I was hoping for links explaining in detail HOW it works, not showing THAT it works.

If it's "like blowing out a candle" it's also not about taking away the oxygen from the fire (you're blowing air into it!). It's taking away the heat by blowing in a lot of cool air. This in contrast to blowing out fires with explosives, which does take away the oxygen for a moment, and probably spreads out the hot fuel in the process.

One major problem trying to put out a real fire this way is that you don't take away the heat or the fuel (the other two parts of the fire triangle). The fuel and skillet in those videos were still cool, below self-ignition temperature. Get the available fuel above that point and the method fails. So putting out building fires and forest fires as claimed in the video is not going to happen, as it will ignite again right away. Foam and water are much more effective here.

I'm only trying to put out a stove fire

My stove fires so far have been caused by overheating oil... half meter high flames in an instant. Putting out the flames is one thing, but you have to switch off the fire under the skillet and let the whole thing cool down a bit to really stop the fire. Such fires on an electrical stove generally mean the oil is at a temperature above the flash point.

It's a fun experiment, but you should be well aware of the real world limitations. Putting out a fire can be done by momentarily taking away the oxygen. Stopping it from reigniting is a different thing.

JonasQ: I'm only trying to put out a stove fire

Okay, I have to be blunt. That will never work. I thought you were thinking along the lines of a candle.

JonasQ: It's for science fair

aarg: Okay, I have to be blunt. That will never work. I thought you were thinking along the lines of a candle.

Its not going to be a big industrial/commercial device, just a science fair demonstration. I think its a great project. I hope you learn a lot from it. Tom... :)

The fire as shown in the video sure that will work and will be great for a science fair demo.

As long as you don't try to simulate an actual stove fire by heating up that skillet until it ignites...

I think a great project would be to try some different types of materials burning and see what it can do. As long as you keep the fires controlled and keep a real fire extinguisher handy things should be safe enough. Sounds awesome as a science fair project.

Honestly, I wish I had thought of doing something like this for my science fair project.

Although, that was also long enough ago I don't think Arduinos existed.

Yes, it will be a controlled fire with an extinguisher handy