nanog mailing list archives

End-user Alert Delivery (was Re: NDAA passed: Internet and Online Streaming Services Emergency Alert Study)


From: bzs () theworld com
Date: Thu, 14 Jan 2021 02:35:04 -0500


(Topic at hand was just building an emergency alert system into smoke
detectors rather than try to come up with some complex
internet-oriented design.)

On January 14, 2021 at 03:56 jra () baylink com (Jay R. Ashworth) wrote:
Last time I looked, consumer residential smoke detectors were still running
off 9V alkaline batteries, which are expected to run the device for 6 months
of 1/99 duty cycle (or less, probably *way* less).

Look again, as I said in the OP most consumer smoke detectors today
are sealed ten year, can't replace the battery (well, not without
surgery.)

I've no idea off-hand what they're using inside tho it's probably not
difficult to find out, $10 and a hammer if nothing else.


An Energizer 9v is rated for 8.4VDC in the very general vicinity of 500mAh.

How does that compare to other factors like ambient temperature which
also affects battery life but we mostly consider "in the noise"?

A lot.  Increasing the alert count from the 1 or 2 it probably is on most
smoke alarms to 2 or 3 a *week*, with LOUD analog speaker alert playback is
going to change that duty cycle, probably, to something like 10/90.
[ All numbers pulled out of my butt for illustration, but probably within
half an order of magnitude. ]

I don't understand what you're designing but all I was suggesting was
a smoke detector with a built in RF switch which upon hearing the
magic signal started squawking "EMERGENCY ALERT!" or similar, perhaps
with a coded word or two like "EMERGENCY TORNADO ALERT!" or perhaps a
brief suggestion to consult your favorite emergency medium immediately
(TV, radio, phone, religious text, etc.)

Or perhaps that would be understood if it ever starts squawking
"EMERGENCY ALERT!" or similar.

Some of them now just start barking "EMERGENCY! EMERGENCY! FIRE! FIRE!
GET OUT OF THE HOUSE" over and over. I hear them go off nearby fairly
regularly so that rings in my head I'm not making it up.


Could we make the battery just a little more powerful? How much power
would a bit of circuitry waiting for a "turn on! there's a new message
coming in!" need?

Well, parsing for EAS on the receiver is going to make its drain non-trivial,
too, I think.

But there are "increasing the battery replacement frequency" problems *and*
"increasing the battery capacity and hence price, not to mention general 
availability" problems balancing that out.

Any way you play it, it has to be an optional model, not a general takeover 
of the field, I suspect, or the "well we just won't bother anymore" factor
takes over.

But none of these power problems etc applies to any of the other
proposed solutions? Phones etc? Or internet connections in general?

Meh, I'd like to hear the thoughts of a smoke detector product
engineer.

My WAG is the only major objection would be that they're already neck
deep in regulatory compliance and OMG this would add another layer of
that, new orgs to answer to, new paperwork, etc.

But so what else is new, ask marketing if it'd be worthwhile anyhow.

Cheers,
-- jra
-- 
Jay R. Ashworth                  Baylink                       jra () baylink com
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates       http://www.bcp38.info          2000 Land Rover DII
St Petersburg FL USA      BCP38: Ask For It By Name!           +1 727 647 1274

-- 
        -Barry Shein

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