Re: Help with 7 Circuit Project?

You don't know anything about me, yet you make these "representations"... Intersting... And you say I'm "abusive". Prove I don't install. Tell us all, please... where do I work?? What's the name of the so-called "distributor" you keep saying I'm a counter clerk at??

I did say I started in the trade in Edmonton though, didn't I?? Seems to me you did ask me that question once... Remember??

Fourth. You started "in the trade" in 1983. You left it in 1996 when you opened your online store. Where's "twenty years"??

As for your statement about glass breaks, there are occasional falses... None of the units I installed ever falsed from "thunder" though.

You see?? I'm glad you explained this more fully. You keep forgetting your participating in a forum of non-alarm types. You frequently make "blanket statements" with little or no explanation, rarely offer any details, and occasionally forget your audiences level of understanding.

Uh-huh... And if you had actually installed any yourself, you'ld know that window treatments such as draperies, blinds, and shutters may require installing the detectors a little closer together than the 25' radius you mention. On ceiling mounted units, you may also run into problems with finishes like oak beams and heavy wainscotting. I'm really glad we've had this opportunity to share our knowledge, Robert!!

Perhaps using a better quality detector (that employs dual technolgy for instance) would reduce the level of false alarms you appear to suffer from.

Not necessarily so. The room could be substantially smaller than 50 feet on a side and still require multiple detectors. It's best to try and locate the units properly. Make sure you purchase the manufacturer's tester (or borrow one from a friendly local dealer). I personally recommend you power the unit with a 12 volt battery and try different locations in the room before mounting the sensor permanently. I also recommend never "maxing" out the "flex" component of the better C&K Intellisense units (in fact I always mount them in locations where the adjustment doesn't exceed 1/4). That will greatly reduce (if not eliminate) the chances of a "false" from thunder.

Check!! Like I mentioned earlier, I'm glad you've taken the opportunity of responding to my post. I felt your information required some "enhancement" to accurately represent the facts. You could have done all this without the bald-faced lies about me though.

Did I say that?? Excuse me if I didn't, but I was referring to glass breaks installed in the same room.

Not as "rare" as you might think... Have you actually ever installed one?? :-))

Or you could use a better quality detector!! ;-)

Nope. Some of us use the Sentrol ShatterPro. They happen to look nice flush mounted in the ceiling. Of course, I understand your aversion to "flush mounting" anything... You did say that once didn't you??

Heh... The "good ones"... :-))

Really?? I thought it had to do with the room's acoustics...

My customers don't usually wrap their rooms in "skin". I'm fascinated... Tell me more... :-))

Ewww... You mentioned the "IEI" word... :-))

Reply to
Frank Olson
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Translation: "Oops!"

It was you who failed to understand. Most of the regulars here are quite intelligent. The only real nimrods are the ASA jerks who come over to try to ruin this newsgroup the way you did the other one. Go away.

Reply to
Robert L Bass

you ruined ASA bAss. and now you're sparkling people skills has got your friends following you wherever you go to converse with you. you can run but you can't hide.

Reply to
joe

Uh-huh... They're all "experienced" alarm installers.

Hahahahahahahahahahahahahahahahahaha!!! That's rich!! ASA has been the way it is long before I came along. You're too funny, Robert!!

Reply to
Frank Olson

If I understand you correctly, I can set up a network of directional, skyward pointing, weather-proof microphones, balance their output at a central junction box also containing a small circuit board with logic to trigger a relay if all microphones hear a very loud event simultaneously.

While it's likely the thunder would be directional and generate large "pulses" from each microphone, some would be louder than others. It would be interesting to mount microphones on all four corners of the roof and feed them into a digital multi-track recorder and the superimpose the wave forms to see if they correlated with my own estimates of the direction.

That's pretty remarkable. I shouldn't be surprised since DragonDictate can differentiate my dog's many barks far better than I. "Wood, rough, mark, hack, '0', been and through" among others.

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Is gone, ironically, what's there is:

Savoy Software offers a complete suite of risk management and security solutions to protect financial, physical and human assets.

Can't get away from security. I seem to recall Cyberhouse walked The Green Mile. Are they no more?

I would expect that the decibel level of the sound itself would be unique, but it might be useful to tie its output to a VLF lightning detector to be certain it's a storm that's being detected, and not fireworks or backfires.

Yes - and I just found some great sample circuits for VLF radio lightning detectors:

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Thanks for your help, Marc!

-- Bobby G.

Reply to
Robert Green

It depends a lot on the proximity of the strike. Distant, "rolling thunder" (apologies to Paul Schrader) is composed of a primary sound followed by a long series of echoes from terrain nearer the strike than the listener. Closer strikes are easier to locate but not always. Sound waves may be less than ideal for localizing because they reflect off of and bend around solid objects.

If you really want an accurate picture of the lightning situation, buy a storm scope. Better ones will display direction and distance of strikes. Interfacing the scope to your security system may be a bit of a challenge, but if you're willing to install a system of microphones on the corners of the house, it shouldn't be much harder to deal with the scope. Cost may be a bit of a factor. Strikefinder models range from ~$3800 up. :^)

Reply to
Robert L Bass

That's an interesting idea too. Sound travels ~1150 feet/second so (eg) a 20 hz wave is about 56 long. So sounds from the same source reaching locations ~28 feet apart cancel. So as you suggest, I'd think you'd still need to identify the entire 'signature' and not just compare instantaneous amplitude.

Which is what I was referring to, namely, using software to identify a characteristic sound from a single microphone. Savoy's Cyberhouse's Listen.exe can do this. There are also commercial, scientific, and freeware programs to do this that might be adapted. Google on "sound recognition"

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As I noted previously, the sound of lightning-induced thunder is complex and variable.

See:

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HTH ... Marc Marc_F_Hult

Reply to
Marc F Hult

That's certainly a consideration for building a 4 input comparator circuit. If I designed the circuit so that a capacitor was charged by the microphones' output for 1/x seconds wouldn't that overcome the out-of-phase problem? It would enable me to "accumulate" the thunderclaps.

Yes, I understand that. It works like DragonDictate, except that instead of putting a word on the screen in response to a "sound match" Savoy's program allows the controller to take an action. I assume, based on my experience with Dragon, that it's not 100% reliable without training.

I think I'm going to spend a little more time modeling the problem. I want to detect thunder mainly to prevent false alarms from my glass break detectors. Since, as you point out, the audio "signature" of thunder is highly variable, it seems it would be pretty futile trying to make a sound match. It would also require PC horsepower, and I'd like to see if a very simple hardwired circuit could also do the trick. I think what you suggested earlier in the thread (some op-amps and gates) would work very nicely simply based on the amplitude of the sound. It might also be necessary to filter out all but the lowest frequency sounds and, as you pointed out, compensate for possible cancellation of the sound waves.

Yes, agreed. Sound pattern matching is not a good solution for a number of reasons. But four microphones, a few IC's and stuff from my junkbox might work. I have to decide whether to amplify the signals close to the microphone (probably best since it would be more likely to compensate for difference in output level due to line length) and how to test the circuit.

-- Bobby G.

Reply to
Robert Green

It can be made to be ~100% reliable in detection. Problem is with falsing.

Seems to me that you could eliminate most falses by ANDing the output of the glass-break sensor on the monitored window with the output of an ultra sensitive (i.e., "too sensitive") glass-break on an upper floor away from the monitored window.

Or as you suggest, the output of a microphone --> amp --> bandpass filter

--> comparator, which could also be mounted on a remote window pane. (IF upstairs window rattling, THEN ignore patio door glass-break.)

Marc Marc_F_Hult

Reply to
Marc F Hult

Yes! This is what makes Usenet great - the exploration of ideas. You're of course right. The simplest solution is a GBD (glass break detector) on an upper floor that's way too sensitive. If that goes off along with a first floor GBD, then it's probably lightning because the likelihood of a burglar smashing two windows in such disparate locations simultaneously is pretty darn low.

Yes - precisely. I'm still fascinated by the idea of mounting microphones at the four opposing house corners and processing the output via PC. I can even camouflage the deployment by claiming to go up and clean the gutters!!!!! (Of course it means I actually *will* have to clean them, but it's a small price in the name of science. I'd love to be able to look at the same thunderclap through four different mikes. Any suggestions on deployment or microphone selection?

-- Bobby G.

Reply to
Robert Green

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