Re: Very sensitive PIR's or DualTech?

["PatrickLidstone" <patrickl@xxxxxxx>]

--- In ukha_d@y..., "psghome2002" <psghome@h...> wrote:
> My question is - has anyone found a suitable PIR for this task i.e.
> triggers really quickly (without too many false detections) and
> looks good on the wall?

Yes - you can buy just the active part of the PIR from
Maplins/Farnell. Measures about 1" square, with a domed plastic
bubble, costs about a fiver, outputs 5V logic. Without any kind of
fresnell (sp?) lens, they are super sensitive to movement. In
security applications, the sensor would have a "double strike"
action
added to minimise false alarms (and NO/NC contacts + anti-tamper)
circuits added in addition to the lens. I imagine you don't care too
much about false triggers if you are just controlling lights -
sunlight may be a problem in your pad! Alternatively, look to
position overhead pointing down to detect heads.

Seems to me there is a scope for a "super PIR" which includes:
security PIR, occupancy PIR, camera (ok I know you can get these
already), dallas temp sensing, possibly light sensing, bi-directional
IR and perhaps a minature speaker for announcements. With the
possible exception of the speaker it should all fit in a conventional
PIR housing with no problem. The non-security bits could then be
multiplexed to save cable...

Patrick