Hmm.....ThorGuard.

[JasonC]

Cool! Four salad bowls and a J.C. Whitney horn! Does it play Dixie or La Cucaracha? Could someone set it off by building up a large static charge (portable rug and rubber-sold shoes) and touching the bowl?

Doubt it. The computer and software that powers the ThorGuard is apparently very powerful and accurate. Like I said, I haven't ever heard of any complaints about these units. Granted plastic horns are cheap, but they wont rust, and a real set of air horns would be unfeasible for the application.

[Elliott]

Was thinking about building this for fun.

http://www.electronics-lab.com/projects ... index.html

I built one of those for my Year 10 science project. Failed miserably though, probably because of my shotty point to point wiring.

That page is just a copy-cat of the original here.

Yeah, I saw that one too....both work from a resonant tank circuit.

Here's another method....ionization: http://www.matchrockets.com/earth/lightning.html

I mentioned this one in a previous post though.

[Justin]

Was thinking about building this for fun.

http://www.electronics-lab.com/projects ... index.html

I built one of those for my Year 10 science project. Failed miserably though, probably because of my shotty point to point wiring.

That page is just a copy-cat of the original here.

Yeah, I saw that one too....both work from a resonant tank circuit.

Here's another method....ionization: http://www.matchrockets.com/earth/lightning.html

I mentioned this one in a previous post though.

Cool, but I rather not play with smoke alarm pellets.

I have a taped recording of a documentary which includes various lightning rods in testing if y'all are interested in seeing it...

Ill have to find and capture it.

[Robert Gift]

What are smoke alarm pellets?

YES, I'd love to see such a video. Thank you, Justin

[Justin]

What are smoke alarm pellets?

YES, I'd love to see such a video. Thank you, Justin

Ionization smoke alarms use a small radioactive pellet (Americium-231 I think) to detect the presence of smoke particles in the air. That's why some have the radiation hazard symbol on a little black piece in the alarm itself, and on the casing.

But as I've said before (and the NSW Fire Brigades have confirmed this), Ionization alarms are useless in fires that burn quickly.

Photoelectric alarms (no radiation hazard symbol) are sensitive to both smoldering and quick-flash fires, and do not use a radioactive element.

[Jim_Ferer]

If the ThorGuard is like the lightning detectors used for construction sites doing blasting (inducing currents in the leg wires is not considered cool) then there's a small radioactive element that ionizes the air around it; lightning in the air around it interferes with the ionization and sets off the alarm. However, there are new kinds of detectors and they all have limits. This is a quote from the Wikipedia article:

"Also, since a personal lightning detector is triggered by EMPs, interference from other EMP-emitting devices (such as electronic equipment, appliances, nuclear weapons, fluorescent lights and even car engines) can sometimes result in either false alarms or missed strikes." [emphasis added]

I just hate it when atomic bombs interfere with my lightning detector and give me a false alarm!

[Justin]

I just hate it when atomic bombs interfere with my lightning detector and give me a false alarm!

Yeah, me too; but I'd be kissing my backside goodbye if that ever happened intentionally.

[Robert Gift]

Ionization smoke alarms use a small radioactive pellet (Americium-231 I think)

Yes. Please note that it is not Australium!
I thought your pellets generated smoke.
I want to produce a lot of smoke to observe how it enters the 2t22.
I assume it will form an excellent tight vortex below the bottom intake tube.

But as I've said before (and the NSW Fire Brigades have confirmed this), Ionization alarms are useless in fires that burn quickly.

No. they are still good. They are better at detecting fires producing little smoke.

Photoelectric alarms (no radiation hazard symbol) are sensitive to both smoldering and quick-flash fires, and do not use a radioactive element.

All of the alarms in our house are ionization type.
They do make both ionization and photoelectric alarms.

[Justin]

But as I've said before (and the NSW Fire Brigades have confirmed this), Ionization alarms are useless in fires that burn quickly.

No. they are still good. They are better at detecting fires producing little smoke.

It was one or the other, wasn't completely sure. Ill have a look for that doco tomorrow.

[Elliott]

What are smoke alarm pellets?

YES, I'd love to see such a video. Thank you, Justin

Ionization smoke alarms use a small radioactive pellet (Americium-231 I think) to detect the presence of smoke particles in the air. That's why some have the radiation hazard symbol on a little black piece in the alarm itself, and on the casing.

But as I've said before (and the NSW Fire Brigades have confirmed this), Ionization alarms are useless in fires that burn quickly.

Photoelectric alarms (no radiation hazard symbol) are sensitive to both smoldering and quick-flash fires, and do not use a radioactive element.

It's Am-241, and here is some info: http://www.uic.com.au/nip35.htm