Re: Sensors for doors & windows & ...

[Chris Hunter <cjhunter@xxxxxxxxxxxx>]

ignoring the prices, all these look interesting :

http://www.usdigital.com/products/products.shtml

http://tinyurl.com/2a8b9y

Chris


On 28 Oct 2007, at 20:08, Chris Hunter wrote:

> 'wonder if something like this would be better than a potentiometer -
>
> http://www.usdigital.com/products/s4/
>
> with the string-approach, that is ...
>
> Chris
>
>
> On 28 Oct 2007, at 12:02, Chris Hunter wrote:
>
>> going a bit further ... maybe a string run between a point on the
>> door & spring-unit in the frame (or the other way around), to
keep
>> the string in-tension, would work, the string being wound-around a
>> potentiometer at some point between the two ends ... with an
>> additional pulley, the spring & the potentiometer could be
hidden in
>> the frame, or the door ...
>>
>> a linear slider potentiometer might be an alternative ...
>>
>> not sure about duty-cycle ...
>>
>> hmm, could be worth an experiment ...
>>
>> Chris
>>
>>
>> On 28 Oct 2007, at 11:41, Paul Gordon wrote:
>>
>>> 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
>>
>>
>>
>>
>>
>



[Non-text portions of this message have been removed]