At 11:44 PM 5/5/2015, you wrote:
>Questions:
>
>1. Would you expect the arrangement described below in a domestic applianc=
e
>(Say a halogen bulb based desk lamp).
>
>2. Would you expect it to meet regulatory standards?
>(Bonus - what standards does or doesn't it meet. )
>
>3. Is it safe?
>
>4. Would you have such in your home?
>
>5. Do you know f you have one?
>
>*Appliance:*
>
>Domestic market appliance.
>12 VAC 2A+ iron core transformer
>Assume transformer meets requlatory requirements for isolation etc  - ie
>there are no short to mains or similar issues.
>This is about the low voltage aspects.

Hi, Russell:-

Here's a couple photos of something that's over my head (literally)=20
as I write.

http://www.speff.com/photo2.JPG
http://www.speff.com/photo1.JPG

There are several hanging fixtures (not shown, but just below=20
photo1.JPG) that carry
MR11 halogen or equivalent LED bulbs to light my desk surface. The=20
wires strung across
the ceiling are insulated with clear PVC (speaker-wire type=20
insulation) and carry no
approval markings- and the metal clamps and the terminals in the supply are
non-insulated and 12V is exposed. Dusting the wires would expose the=20
cleaner to 12V
every time. The supply is a switching supply "transformer" so fully=20
isolated and
carries normal approval markings for this market (UL/CSA). Naturally,=20
the supply is
short-circuit protected (it just shuts down if you overload or short it).

So I would say the answer to all the questions 1..5 is "yes". 2 is a=20
bit trickier--
I have a suspicion it would meet requirements but may not have been=20
subjected to
full testing- in particular the part after it becomes low voltage and=20
galvanically
isolated.

Best regards,
Spehro Pefhany

--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.