Re: Re:Smoke Alarm

[Chris Hunter <cjhunter@xxxxxxxxxxxx>]

interesting ... when it comes to it, what opto-isolator &
relay=20=20
packages will / might you use ... I guess there must be standard=20=20
units for such things, without having to resort to chips & own-=20
boards ... and I could imagine needing a handful, one way &
another=20=20
(we've an old reel-to-reel tape-recorder, for example, that has a=20=20
parallel interface for controlling it) ...

actually, that's a thought, too ... some of our other old machinery=20=20
has RS232 interfaces for the same purpose, and having a Parallel-to-=20
RS232 interface might be an option for Idratek to work with them as=20=20
well ... using digital input / ouput modules ... ... 'wonder if=20=20
there's an obvious source for such units ?

Chris

On 16 Oct 2007, at 11:41, JonS wrote:

> I spent ages looking into smoke alarms and in the end went for a 9V Ei
> interlinkable set of heat and smoke alarms.  The link is any old=20=20
> twin core
> conductor.  The cable you have found looks like the pukka fire=20=20
> protected
> stuff for commercial premises etc.  If you want that, go for it, but I
> didn=92t feel that level of protection in my house, if the cable
has=20=20
> burnt
> through before we get out then we=92re in big trouble :-/
>
> Another thing I found with commercial stuff was that the
detectors=20=20
> didn=92t
> contain sounders, so more wall/ceiling rash plus more expense.
>
> I was put off the 12V Ei interlinkable alarms that I could have=20=20
> powered
> direct from Idranet as they were about 50% more expensive that the 9V
> version with a 10yr battery.  The only disadvantage of this is
that=20=20
> the link
> is not a volt-free contact but a 6-9V signal.  Opto-isolator or relay
> required to do the link into idranet.
>
>
>
> HTH, but note I haven=92t fitted them yet!
>
>
>
> Jon