Dean Heighington wrote:

As mentioned, transformer are included but are also the plug
for each kit and NO, they're not externally rated!

Ah, OK wall warts then...

Hmmm, don't fancy that much...


Why's that?

It is a lot of hassle to dig up a SWA and then make a waterproof
junction to it underground etc.

Are all these transformers supplying the same sort output (i.e. 12V AC
for example)?


Yes they are, I think its all 10V AC.

OK looking at your specs from the other post, the LED lights both have a
12DC Supply, the ordinary halogen ones use a 12V AC supply. There is
nothing to stop you running the AC lights on DC since they should just
be ordinary incandescent bulbs (the reverse is not true since the LEDs
won't like having AC stuffed up em!)

So you need one 12V DC supply that can handle a total current.

Due to other, ongoing building works currently happening, I do have an
available cable route from the garden, through the kitchen, garage
and into the understairs cupboard where the consumer unit is. This is
all via 2" conduit hidden behind fixtures and fittings. Are you

No need for a dedicated circuit here - we are talking about a tiny load
overall - less than 100W in total.

suggesting that I add a new circuit to the consumer unit, using one
of the spare 'ways', and fit a PSU which converts 240V to LV (replacing
the kit supplied transformers) and suitable for providing LV to all
3 lighting circuits in unison? And then interrupting the LV supply to
each by installing the desired switches?

Yup that would be a solution...

Sounds like a potential solution and seems proper. How do I go about
calculating the requirements and selecting the correct components to
allow this?

Personally I would start by measuring the actual current draw of each
set of lights (with multimeter if you have one)

Does not say if they are AC or DC, but at a guess they will be AC. Not
sure what the LED lights will expect however. Assuming they all want 12V
AC then an electronic LV lighting transformer of the type used for
internal halogen lighting could supply enough juice for the whole setup.
One hefty ish cable run outside from the house to the deck, switched and
then direct connection to the lights.


Is this an alternative to the above or in addition? It sounds

It was a continuation of the above - just suggesting a cheap and
available source of power supply - but now we know two sets require DC
it is not such an attractive solution since the output of lighting
transformers are AC and not DC and hence unsuitable for the LED lights.

like an option as the biggest problem I have is the kit supplied
transformer plugs and it seems plausible that there would be a
transformer on the market that would cater for all three circuits.

There is a huge choice of PSUs of various types available. Your
requirements would seem to point toward a fairly high powered DC one at
the moment. Perhaps a small computer PSU would do the job since these
will knock out a good number of amps at 12V. You need to find out how
much each of the clusters of lights are using first before getting into
too many more specifics (computer PSUs also have a minimum load beneath
which they will not work).

Again, I lack experience with LV systems, but assume that such a
device would have an array of (2 or more) connectors and converts
240V on one side to multiple LV outputs on the other? I can then
install switches on each LV feed?

If you had a PSU with enough output then you could simply take your
three feeds from it and then switch them.

Have I understood you correctly? Which do you think is more
appropriate and cost-effective?

Using the ones you have is the most cost effective, however it may not
be the most appropriate.


--
Cheers,

John.

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