Re: occupancy PIRs

[Kevin Hawkins <lists@xxxxxxxxxxxxxxxxx>]

HI Stephen,

A while back I looked into doing a bulk buy for the occupancy
sensors, the same ones that Simon had offered. I had hoped he would have
been able to step in and do this but he seems pretty difficult to
contact nowadays. He's undertaking a large renovation project so he's
well occupied there for a while I guess. These are available as a trade
purchase in quantities of 50 units min order though .  (This was a
special as in actuality their min order is 100 - the price is circa £30
ea). For the sensitive versions a special run was required by the
manufacturer. The manufacturer normally sells via security distributors,
not small trade accounts.  The issue was complicated as there are  two
(or more) versions with different sensitivities . For intelligent
occupancy detection  then the more sensitive are probably desireable but
if you want more resilience against false alarms the standard ones are
the way to go.  The sensistive variants may well ahve sporadic triggers,
if this isn't a concern or can be software qualified then they are great
for ensuring lighting stays on with minimal movement.  However most
commerical occupancy lighting implementations use the less sensitive
variants I am told. As these are for meeting rooms etc movement tends to
be dependable. I have been unable to find from Simon which he used and
they are marked identically.

My problem was that  most people wanted one to try and then had
orders for 2 or 3  so I was a way off the mark quantity wise and there
was a risk attached that people might not buy any more than a couple.
If a dozen or so people had wanted smaples it might have worked but
there were only 3 takers.

I may revisit this if there is enough interest - the alternative was
to get hold of some samples at a higher price to satisfy the 'eval'
units people wanted but their were only a couple of people who
originally contacted me and they went quiet when asked on quantity  or
samples at higher cost.

I have also been looking at some very miniature occupancy sensors -
about the size of your little finger - but they require a little more
careful interfacing as they give an open collector type output and
require a stable regulated voltage supply. Their mounting  options are
not 'end user PIR product' type either.  They are available in black and
white with different  detection charcteristics eg wide , narrow,
corridor etc. They are not quite as sensitive as the  other larger types.

Kevin

Stephen wrote:

>Please can someone recommend a good occupancy PIR for HA use? I guess
>it needs to be 12v dc or be able to switch 12v dc? I know Simon Coates
>sold many to list members. Can anyone climb on their step laddder and
>read the make and model number for me? It's hard to search on google
>or wherever when I'm not quite sure what to search for; a make/model
>would help me enormously. Thanks.
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