RE: Sensors for doors & windows & ...

["Paul Gordon" <paul@xxxxxxxxxxxxxxxxxxxxx>]

I'd already thought of the very same idea, however, I'd rather thought
the hidden variety would be preferable.. You may have seen the hidden
type, - it usually consists of a spring box which gets mounted in the
door frame on the hinge side, and a tensioned chain issues forth &
attaches to the hinge-side of the door.

When the door is closed, no part of the mechanism is visible, - much
better for a domestic environment, where I can't really imagine many
SWMBO's being too happy with the rather industrial type shown in the
picture...

Again, I would imagine it shouldn't be beyond the wit of man to enhance
this design to sense how much of the chain is fed out, which equates to
how open the door is...

Paul G.



-----Original Message-----
From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf
Of Rob Iles
Sent: 27 October 2007 20:55
To: UKHA Group
Subject: Re: [ukha_d] Sensors for doors & windows & ...

How about - - for doors, and non-sash (sliding) windows --- how about a
pivoted arm and a potentiometer?

I'm thinking of something similar to the "soft-close" mechanisms
you
often
find on doors in commercial premises - which consists of a box screwed
to
the door (hing side) - and two arms, hinged in the middle. the mechanism
(spring?) inside the box cause the door to close when you let go.
(hopefully, by now, you all know what I'm talking about!) :)

a picture may help - - http://tinyurl.com/yok7h4


well, if you replace the spring/tension mechanism with a potentiometer -
you'd get an analogue reading of door position. feed into an A-D
Converter,
and with a little calibration, you could measure the exact angle /
amount by
which the door is open.

The commercial products are quite bulky, and might not fit into your
home
decor (decreased SOAF) - - but they're the size they are as they need to
apply considerable torque to close the door (due to the location of the
mountings).

You could probably build something significantly smaller, as the two
arms
only need to turn a potentiometer - mount it in a discreet box, and away
you
go :)

If you think this is a fantastic idea, then I hereby claim - in public -
all
IP rights/copyright/patent pending ;) .....and may (seriously) consider
having some made!

Thoughts?

Rob


On 10/27/07, Chris Hunter <cjhunter@xxxxxxx> wrote:
>
>   Gerry's boards ... presumably as in :
>
> http://www.rgbled.org/maxbotix/index.html
>
> up to twelve sensors per board sounds pretty useful !
>
> our PC has four RS232 sockets, one maybe two being spare ... so could
> be good for us, too (assuming I can link to Cortex) ... !
>
> Chris
>
>
> On 27 Oct 2007, at 12:23, Kevin Hawkins wrote:
>
> > I'm intending using some of the Maxbotix ultrasonic sensors
pointing
> > slightly diagonally across the doorways. These then provide a
> > direction
> > indication for a person moving into or out of a room (short to
> > long or
> > long to short reading) and based on distance you can elimate
outside
> > false trips. I use Gerrys boards, only played so far but seems
> > viable,
> > fortunately I have deep doorways in walls often 3 foot thick. . A
> > top
> > mount sensor might even identify people based on height- or the
dog
.
> >
> > I also have some Pulsor -strain sensors arriving any day now -
which
I
> > hope to use on the stairs and a couple of doorways.
> >
> > K
> >
> > Chris Hunter wrote:
> >>
> >>
> >> 'thinking of sensors for doors & windows ... and the
limitations of
> >> the reed-switch (just open or closed & no certainty on
what it's
> >> telling about the door, unless perhaps it's attached to the
locking
> >> mechanism in some way - which can't see how to do as a
retro-fit)
...
> >> was trying to think how else ... strain-gauge ... laser +
mirror
...
> >> all have just-as-bad limitations ... hmmm ...
> >>
> >> 'wonder if PIRs are all the same ... obviously not, but in
the
sense
> >> of being designed to pick-up just movement .... are there
some that
> >> are designed to pick-up position, say, or presence not
associated
> >> with movement, or movement of hard but not soft objects, or
... ?
> >>
> >> with MHVR, having doors or windows open might be expected to
affect
> >> the pressure in the house ... so, all closed => some
pressurisation,
> >> maybe, depending on the relative speeds of the inlet &
outlet
> >> fans ... 'wonder if adding air-pressure-sensor(s) to each
room
could
> >> be useful ... picking-up both level & fluctuations ...
and so doors
> >> open, people moving-about, curtains wafting, pesky flies,
> >> whatever ...
> >>
> >> micro-phones are air-pressure sensors, of course ... wonder
if a
> >> broad or limited bandwidth one would be best ...
> >>
> >> hmmm ... would fuzzy logic be the thing, to make it work ...
looked-
> >> up Wiki, but 'am really none the wiser, 'though it did
mention
> >> pattern recognition as being an application for it ...
> >>
> >> rambling, sorry, but I feel there's a glimmer here !
> >>
> >> or maybe I'm clutching at straws ...
> >>
> >> Chris
> >>
> >>
> >
> >
> >
> >
> >
> >
>
>
>


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