Re: Re: LD11 - Can it be altered to operate using 12v dc or 24v dc

[ian.bird@xxxxxxxxxxxxxxxxxxxxxxx]

I hear what you say (practising my corporate speak ;-)) but tbh the price
of the relays will be small. I don't have my price lists here but you
should be able to get the relays for a quid or so each.

The next challenge is to mount them safely. As it happens my central
heating switch thingy does just what you want. I take a 12 volt signal
which switches a relay which in turn carries mains voltages. Whilst I would
not recommend you to use the exact design the addition of an opto isolator
(no mains down the Cat5 cable) would not be a big deal. You can even get
professional printed circuit boards made for around 30 quid for 4
(depending on size you may get more).

So, relay and socket, opto isolator and socket, some connectors for the
various wires and a box to put it/them in. You should be able to see that
for a reasonable cost. Taking a worst case of around a tenner each then 10
circuits would only be a hundred quid + some time and effort.

If you are interested then I would be happy to help with the PCB as not
everyone has the software (or inclination) for that. Having said that
www.olimex.com/pcb will accept files direct from Eagle
http://www.cadsoft.de/ who do a
shareware version of their tool. Just the
time to learn it ;-(

This would be a nice safe integrated solution where any failed components
could be replaced very easily.

Ian





"big_red_748"
<john.macnamara@globalcr        To:       ukha_d@xxxxxxx
ossing.com>                     cc:       (bcc: Ian Bird/CV/Novartis)
Subject:  [ukha_d] Re: LD11 - Can it be altered to operate using 12v dc or
24v dc
09/03/2005 02:27
Please respond to ukha_d










Thanks Frank,

The only problem is that buying a relay for every lighting circuit
will add a fair whack to the cost.

I want to keep the cost down as I am sure we all do.

Cheers,


John



--- In ukha_d@xxxxxxx, "Frank Mc Alinden" <fmcalind@b...>
wrote:
> Hi John
>             I believe the ld11 button connections are at mains
voltage
> ...240v........
>
> What you could do is use the cat5 cable to operate small industrial
type 12v
> dc relays back at Node 0 and connect the contacts of the relays
across the
> ld11 button connections....????
>
> HTH
> Frank
>
> ----- Original Message -----
> From: "big_red_748" <john.macnamara@g...>
> To: <ukha_d@xxxxxxx>
> Sent: Wednesday, March 09, 2005 5:17 AM
> Subject: [ukha_d] LD11 - Can it be altered to operate using 12v dc
or 24v dc
>
>
> >
> >
> >
> >
> > I am having an extension built and am taking the opportunity to
cable
> > out for home automation.
> >
> > To keep costs down but allow for future upgrading, I was planning
to
> > install a push button momentary switch at the light switch and
run 2
> > x CAT5E cables (the extra one for future expansion) from each
light
> > switch back to node 0.  Also to run each lighting zone back to
node 0.
> >
> > Using low voltage over the CAT5E to switch the dimmer on / off
and
> > also to dim.
> >
> > The problem is that the rail mounted LD11's operate at mains
voltage
> > so I either have to run a mains cable as well as the 2 x CAT5E's,
> > convert the LD11's to run on dc voltage or find another solution!
> >
> > 1. Does the LD11 convert the mains voltage down to a lower dc
voltage
> > internally?
> >
> > 2. If so, is it easy to remove this and therefore control the
unit
> > using 12v dc or 24v dc?
> >
> > 3. Am I missing an easier solution?
> >
> > Thanks,
> >
> >
> > John
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >