RE: Assistance for Anosmia

[ian.bird@xxxxxxxxxxxxxxxxxxxxxxx]

Yup, detecting when an LED is on or off is quite simple as long as the
ambient light levels are predictable or better still simply dim or dark.
In the case of a hand held detector this would be quite simple. The
hardware involved is a photo diode, an comparator and micro although a
simple switching arrangement could replace the micro. When I did this I
was counting the pulses rather than simply echoing them. I think the story
and circuit is on my site somewhere, probably under the projects section.

http://www.mollyology.com/index.php

Ian






"Hawes,Timothy Edward \(GEG\)" <haweste@xxxxxxx>
10/01/2005 10:32
Please respond to ukha_d


To:     <ukha_d@xxxxxxx>
cc:     (bcc: Ian Bird/CV/Novartis)
Subject:        RE: [ukha_d] Assistance for Anosmia



Ian,

I didn't recall anything for the UK domestic market, but there will be
plenty in the professional arena :-/
(read expensive)

There's some 110V stuff from the US, try:
http://www.safehomeproducts.com/SHP/SM/methanedetectors.asp
http://www.macurco.com/sh4s1d.pdf

And this for the UK - seems like it has extra "signalling
contacts", not
just an in-built alarm :-)
http://www.sfdetection.com/pdf/SF210_howsafe/How%20Safe%20is%20Your%20Ho
me%20-%20ENGLISH.pdf (glossy brochure)
http://www.sfdetection.com/pdf/Manuals/SF210/SF210%20ENGLISH%20Manual.pd
f (installation manual)

(I started writing this, then googled a bit more, I'll leave it in just
in case you're interested)
I also found this:
http://www.professionalequipment.com/xq/ASP/ProductID.564/id.7/subID.90/
qx/default.htm
At USD 100 it's probably about as cheap as you'll get. Yes it's a
portable tester and the batteries only last a few hours but I reckon
it'd be pretty easy to convert to mains-powered.

What's perhaps the bigger problem is how do you extract the alarm signal
? At least two people on this list have made devices that can detect
whether an LED is on or not (Ian Bird & Frank, IIRC). From the picture
I'm gonna guess the red LED is the alarm one so you could pick up
whether the LED has lit and then generate the appropriate whole-house
alarm. I guess you'd could even tie it into your burglar alarm if you
wished.

I'm not sure *I'd* try to open it and hack the innerds to get the alarm
signal out, but then I'm a dunce at electronics ;-)

HTH,

Tim.


> -----Original Message-----
> From: Ian  Sent: 07 January 2005 21:18
>
> I'm looking for ways to help about the house for someone with
> congenital anosmia - Jenni (swmbo) has had no sense of smell
> since birth.
>
> It's obviously not as serious an issue as having no sight or
> hearing, and we have heard (and made) most of the usual jokes
> and comments - it probably makes it easier to live with me,
> for instance ;)
>
> We have had a couple of cases recently where it's caused
> problems - I act as the house "sniffer" to check when meat
is
> okay to cook, but when I have a heavy cold (as I did over
> xmas) we can end up eating stuff that's not quite right, and
> suffering for it. I also came home a week or so back to find
> the kitchen absolutely stinking of gas - and Jenni blissfully
> unaware, making a sandwich.
>
> We have displays around the house for caller ID etc, so as I
> see it, all I really need are some sensors. There are a
> couple of things to cover - something for the fridge that can
> detect "off" meat and something for detecting domestic gas
in the air.
>
> Has anyone done this before?
>
> Ian.