Re: Cheap and small Break Beam circuit ?

[ian.bird@xxxxxxxxxxxxxx]

Hi Marcus

You are treading the exact same road I did with my kitchen lights. I ended
up using a Maplin beam break unit (MK120) which is 7.99  now I think. I
mounted the LED transmitters and receivers into the door frame and then
moved the main PCB's elsewhere and hid them. It comes with a buzzer but a
transistor and resistor made that silent and created a switch. I have this
attached to an HV input and then X-10 turns on the light. This is pretty
good tbh. There is HV code on my site
<http://www.mollyology.com/MyHouseKitchenLights.htm>
as it has different max on values depending on the time of day etc.

Enjoy

Ian




---------+------------------------------>
Marcus Warrington
<marcus.warrington@
mis-es.com>
Sent by:
ukha_d@yahoogroups.
com


12/07/2006 14:37
Please respond to
ukha_d

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To:       ukha_d@xxxxxxx
cc:       (bcc: Ian Bird/CV/Novartis)
Subject:  [ukha_d] Cheap and small Break Beam circuit ?
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Having now got all the lights (except the kitchen/Utility) on X10
circuits I've now started to think about how to implement occupancy
detection. Originally I was going to use ceiling mounted 360 degree PIRs
but having trailed them I find that they're sensitivity isn't up to
detecting someone walk into a space in time to get the light on (not
helped by the X10 comms latency). The only way I can get anywhere near
is to mount them directly over the entranceway since they appear to be
more sensitive directly underneath the sensor. So, next thought was to
mount them centrally in the room but then use a break beam across the
entranceway (door jam) as a primary trigger. So does anyone know a small
simple break beam device or circuit that I could install across a
doorway. Needs to be small and sit relatively flush with the surface
(the door jams are wood so I can rebate a little bit) and be easily
connected to HomeVision.

Marcus