Re: Re: motion detectors: need some input

[Tom Van den Panhuyzen <tomvdp@xxxxxxxxx>]

Hi Kevin,

On Tue, 11 Jan 2005 01:45:14 +0000, Kevin Hawkins
<lists@xxxxxxx> wrote:
> Tom Van den Panhuyzen wrote:
> Most PIR's don't usually generate a voltage - they are usually like a
> switch in that they 'connect' whatever you feed in to their output
when
> they are triggered (or possibly the reverse, removing the signal when
> triggered). hence if you feed 230V in then 230V comes out.. The
> 'contacts' have to be rated to handle the voltage in use and to carry
> the current drawn . For connection to a Viom/Netiom you can't use
mains
> voltage directly so the lighter duty 12V/24V rated ones are probably
the
> ones to go for. This level of signal can directly attach to a
> VIOM/Netiom input - (the current is not important here at all). It
would
> be possible to use mains switching PIR's by making them switch a relay
> and then use the contacts on the relay into the Netiom. The relays
> isolate the mains voltage from the contacts ,and hence the Netiom,
> making it useable and safe. However this means mains wiring outside
> which always needs more care and it is harder to wire using the relay.

Now I am confused... If the contacts in the PIR are rated 230V to
indicate that they can handle such a voltage, can they not just as
well open or close a 12V load ?

Is this correct:
- there is a power circuit for the PIR to make it operate
- there is a power circuit for the NETIOM
- there is a power circuit that can be opened and closed by the PIR
and tested for open/closed by NETIOM ?  This is not "automatically
provided" by NETIOM ?

Tom


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