Re: Re: Beam Breaks - worthwhile?

[ian.bird@xxxxxxx]

One of the electronics mags I got today has a simple little project that
works from a reflected signal. It changes an output state depending on
whether a 'body' is there or not. Range is adjustable but I don't know how
much by. It was the same mag that has the PIC weather station project in
it although I cannot remember its name. Might be the same sort of thing as
in hand driers etc. I have not even read it yet so no details available -
sorry.

Ian








"Paul Robinson" <ukcueman@xxxxxxx>
14/08/2003 15:56
Please respond to ukha_d


To:     <ukha_d@xxxxxxx>
cc:
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?


>
> Hi Shane
>
> I use beam breaks in a couple of door around the place with 100%
> reliability. About now I should say I use them for switching lights
not
> occupancy detection. If you plan to use the PIR system to do lights
you
may
> well be annoyed by the detection delay which means you have already
walked
> into something by the time the light comes on. Beam breaks solve this
> problem pretty much but are not always suitable depending on your
house
> layout. Don't forget light level detection if you plan to go for light
> control. If it is daylight you may not want to turn on the lights
depending
> on other factors e.g. ambient light level. Here is some details on
this
> project http://www.mollyology.com/MyHouseKitchenLights.htm
>
> I have used a very slightly modified version of the Maplin beam breaks
(
> http://www.maplin.co.uk product
code MK120) and have mounted the IR LEDs
> remotely from the PCB boards (cos they are big and ugly). I only use
about
> 6 feet of cable but you could probably mount them further away. The
> modification bit means they switch a reed relay rather than sounding a
> buzzer.
>
> Ian
>
>
> Hi Neil
>             Ian Bird could be the man to speak to ...Check out the
link
to
> Ians project it might help...
>
> http://www.mollyology.com/ProjectsBabyPaws.htm
>
> HTH
> Frank
>   ----- Original Message -----
>   From: Frost Neil
>   To: 'ukha_d@xxxxxxx'
>   Sent: Thursday, August 14, 2003 9:22 PM
>   Subject: RE: [ukha_d] Re: Beam Breaks - worthwhile?
>
>
>   Are there any someone could recommend?
>
>   -----Original Message-----
>   From: mark_harrison_uk2 [mailto:mph@xxxxxxx]
>   Sent: 14 August 2003 10:54
>   To: ukha_d@xxxxxxx
>   Subject: [ukha_d] Re: Beam Breaks - worthwhile?
>
>
>   Shane,
>
>   I'd install them. It's a real pig to fit them retrospectively, and
>   multi-mode occupancy sensing is always going to beat single-mode.
>
>   Regards,
>
>   Mark
>
>   --- In ukha_d@xxxxxxx, "Shane Harrison"
<shane.harrison@p...>
>   wrote:
>   > Hi there,
>   >
>   > So I am in the final planning stages of the new house and the
>   question
>   > is should I go to the trouble of installing beam breaks on the
>   internal
>   > doors (where sensible)?  Are they really useful or should I
stick to
>   > multiple PIR's (one for security one for occupancy) if I wanted
to
>   have
>   > occupancy detection. I am thinking that technology must improve
in
>   this
>   > area soon and hence camera occupancy might eventually be a
better
>   > approach or some other smart technology.
>   >
>   > I would appreciate you learned thoughts?
>   >
>   > Cheers
>   > Shane






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