Re: Re: Beam Breaks - worthwhile?

["Paul Robinson" <ukcueman@xxxxxxx>]

I was thinking specifically about doors - so only short distances. The idea
being that that you would only have to wire to one side of a door or just
to
the top of it. I was wondering if this was practical/possible for HA.

Keep us informed about Phaedrus though!

URL for those interested:
http://www.phaedrusltd.co.uk/system/index.html

Paul
----- Original Message -----
From: "Kevin Hawkins" <lists@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Thursday, August 14, 2003 6:05 PM
Subject: RE: [ukha_d] Re: Beam Breaks - worthwhile?


> Just had a chat with Phaedrus about their motion bar - and first of
all
must
> say what a pleasant surprise it is to talk to a company that wants to
help.
> They went out of their way to see if there's an opportunity for
adapting
> their product to this need - and I shall let you know how this
progresses
as
> one is on it's way here as a free loan.  Have been very pleased too
with
my
> VIOM module I got from them a while back too - (16 Input and 16 Output
via
> serial) - not as clever as IanB's soon to be released xAP enabled
board
> though !! ( they deserve a plug as it's so rare to feel good after a
> telephone conversation with companies nowadays).
>
>             Their original 'beambar' design uses 4 beams because it
was
> designed to be mounted vertically (and allows for several units to be
> stacked) to protect an area eg a window - thus the beams were spaced
> reasonably far apart to be economic in the coverage length - whilst
not
> allowing people (or whatever) to squeeze between. Two beams had to be
broken
> to trip an alarm , which is typical in most vertical multiple beam
> arrangements - falling leaves etc.  The motion sensor came simply from
> seeing a new application using the existing hardware. So this means
there
> was no essential technical reason why the beams couldn't be closer -
or
> indeed that four were needed - I shall have a try at narrowing the gap
and
> see what the effect is. It may well be achievable in a two beam design
as
> well.
>
>             A couple of interesting points were made. The sensors
could be
> mounted diagonally and still sense direction - this reduces the width
> requirement to 15cm. However you need to ensure that beams are broken
in
> order - if for example a middle beam is broken first it gets confused
- if
> you mount diagonally there is an increased risk of this happening - eg
hand
> ahead of body - or carrying something.
>
>             I'll report back in due course..
>
>
>
>             Paul - re your comment below there are some quite fancy
beams
> that work on reflected light, both indoor and outdoor - for example
the
> RetroVisor form http://www.rv-ltd.demon.co.uk
> <http://www.rv-ltd.demon.co.uk/>
 - when they get clever and long distance
> (as this one is 30M ) they get expensive too though.
>
>
>
>             K
>
>
>
>
>
>
>
> -----Original Message-----
> From: Jon Payne [mailto:jgpayne@xxxxxxx]
> Sent: 14 August 2003 16:26
> To: ukha_d@xxxxxxx
> Subject: Re: [ukha_d] Re: Beam Breaks - worthwhile?
>
>
>
> I was thinking also that two may be needed for direction i.e. when you
enter
> the lounge the light comes on, but not when you leave it...
>
> jon
> ----- Original Message -----
> From: "Paul Robinson" <ukcueman@xxxxxxx>
> To: <ukha_d@xxxxxxx>
> Sent: Thursday, August 14, 2003 3:56 PM
> Subject: Re: [ukha_d] Re: Beam Breaks - worthwhile?
>
>
> > Is a receive/transmit pair the only reliable way to do this?
> >
> > ISTR something that was both transmit and receive, relying on a
reflection
> > to operate. Is there such a beast or did I imagine it?
> >
> > ----- Original Message -----
> > From: <ian.bird@xxxxxxx>
> > To: <ukha_d@xxxxxxx>
> > Sent: Thursday, August 14, 2003 3:35 PM
> > Subject: Re: [ukha_d] Re: Beam Breaks - worthwhile?.