Re: PIR control of lights

["Patrick Lidstone <patrick@xxxxxxx>" <patrick@xxxxxxx>]

--- In ukha_d@xxxxxxx, "Rob Mouser" <rmouser@t...> wrote:
> Hi Umar
>
> I know your going to expect me to say this, but..........
>
> If you want reliable detection and no delay between detection and
lights
> on then Clipsal make two excellent PIR detectors that work on the C-
bus
> network. I would still add switches though so you have manual
control,
> the beauty of c-bus is those switches will no the status of the
light at
> all times.

I think the underlying message here is that PIR switching can work
reliably, but that you have to use sensors that are independent from
the security system. Security PIRs are poorly suited to light
switching because of their inbuilt immunity to false alarms - PIR's
optimised for occupancy detection are readily available and do a
superb job. The Matsushita module I have on my workbench at the
moment will detect sub-cm movement over a couple of metres pretty
much instantly, just what you want for this kind of application - and
probably sensitive enough to keep the lights on even if you're lying
in the bath and just wiggling your big toe.

Patrick