Re: PIR's and HomeVision

["Bov" <bov@xxxxxxxxxxxx>]

Ah, even easier - thanks for that Kevin.



--- In ukha_d@xxxxxxx, Kevin Hawkins <yahoogroupskh@...> wrote:
>
> You will use the contacts in the PIR in a 'volts free' way - as per
Jons
> post - do not bring the 12V back from the sensor into HV. These two
> wires attached to the contacts can come back down the same CAT5 so you
> will use 4 wires in all . There will be no connection between/across
the
> CAT5 individual wires at either end of the cable.  The power supply is
> only there to power the electronics of the PIR's and will be totally
> isolated from HV.  Reed contacts just the same - they are just
connected
> to the HV input 'volts free' ie just open circuit / shorted and should
> not have 12V applied.
>
> If you are series connecting the PIR's then you can use an additional
> pair of wires for the other sensor contacts but the power wires will
be
> common. Also if you wish you could use two wires in parallel for the +
> and two for the - to allow the cable to carry more current - but the
> sensors do not draw much.
>
> There is one slight risk you should be aware of and that is lightning.
> It is possible that a storm could induce enough voltage in the CAT5 to
> exceed the input port limitations on HV and this could damage the
input
> circuitry.  You can protect against this with opto isolators but it is
> considerably more complex to wire up.   All the chips on HV are
> socketed, very low cost and easily changeable and so most people just
> live with this.
>
> K
>
>
> Bov wrote:
> > Fantastic - I'll get 2 of those GJD PIRs, a 12v power supply and
a
> > bunch of Cat5 cables to plumb it into my HV unit.
> >
> > Presume I simply run a 12v circuit through each PIR and then back
down
> > the Cat5 to the HV?
> >
> > Can anyone tell me how I wire this up to the HV? I'm sure I can
work
> > it out with a bit of trial and error - just trying to save some
time :-)
> >
> > Also, with a reed switch - can I simply add that in the same way
with
> > a 12v circuit back to the HV unit?
> >
> > Cheers.
> >
> >
> >
> > --- In ukha_d@xxxxxxx, "Simon Coates" <simon@>
wrote:
> >
> >> Bov,
> >>
> >> I use these
> >>
> >> http://www.gjd.co.uk/elite.htm
> >>
> >> Regards
> >>
> >> Simon
> >>
> >>   ----- Original Message -----
> >>   From: Bov
> >>   To: ukha_d@xxxxxxx
> >>   Sent: 09 October 2008 20:57
> >>   Subject: [ukha_d] PIR's and HomeVision
> >>
> >>
> >>
> >>   Can anyone help me with:
> >>
> >>   a) instructions for how to wire an infra red motion sensor
to a
> >>   standard homevision unit.
> >>
> >>   b) I presume it's the same for a reed switch?
> >>
> >>   c) recommend the right outdoors PIR motion sensor to use
and what
> >>
> > other
> >
> >>   kit I need for this.
> >>
> >>   Thanks.
> >>
> >>   Bov.
> >>
> >>
> >>
> >>
> >>
> >> [Non-text portions of this message have been removed]
> >>
> >>
> >
> >
> >
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>



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