On Thu 25 Dec 2008 11:47:28p, E Z Peaces told us...

Wayne Boatwright wrote:
On Thu 25 Dec 2008 04:53:05p, E Z Peaces told us...

Jim Beaver wrote:
"E Z Peaces" wrote in message
.. .
Jim Beaver wrote:
I've got my Christmas tree set up in my living room. A couple of
strings of lights (not those mini-lights, but the finger-tip size
bulbs). Here's the problem:

When I turn on the lights, a loud hum arises from the timer for my
yard sprinklers. This timer is mounted on the outside wall of the
living room. Obviously it's on the same circuit, as the hum comes
and goes when the Christmas tree lights are turned on or off.

The hum is loud. Probably loud enough indoors to wake a light
sleeper from a nap if it suddenly came on. It's even louder, of
course, outdoors near the timer.

The power cords, plugs, and receptacles all seem cool. So I'm
wondering: does this sound like an overloading problem, or more
likely some sort of simple harmonic vibration? Am I in danger of
fire, if everything I can get to seems cool?

I don't know anything much about electrical testing or I'd use a
tester on it somehow. But I don't really know what to look for.

Anyone NOT doing something more interesting on Christmas Eve who
wants to advise me here?

And with that in mind, happy holidays to all here. Thanks.

Jim Beaver
I haven't been able to imagine how the lights could affect voltage
or current in the timer.

Are there valves near the timer? Sometimes a solenoid valve can hum
loudly.
I discovered this morning that the hum doesn't happen in the daytime.
Which leads me, genius that I am, to conclude that it's not the
sprinkler timer but the low-voltage outdoor lighting system timer. I
have no idea whether this affects matters much in terms of safety,
etc.

Jim Beaver
My idea light is flashing! Does an electric eye turn on the outdoor
lights? Maybe the eye is exposed to one of the outdoor lights as well
as light from your tree in the window, and together they hit it with
enough light to shut it off. That brings the light below the
threshold and it turns back on. The frequency of the hum would depend
on how long it took the outdoor filament to heat white hot.


Maybe I've missed something here, but why belabor this situation? Just
plug the lights into a socket that's on a totally different circuit.

All this effort for a temporary lighting situation seems like a huge
waste of time and effort, or do you just enjoy puzzles?

Can you explain how the Christmas tree is affecting the outdoor lighting
in a way that running an extension cord to another room would prevent?
It sounds like a huge waste of time and effort.


No, I can't, and I wouldn't waste my time trying if the Christmas tree
doesn't affect the outdoor lighting by plugging the tree into a totally
different circuit. If it were a permanent situation, then it would be
worth the effort.

I don't know if this question has been answered, but does plugging anything
else (like a table lamp or radio) into the outlet where you plugged in the
tree cause a similar situation with the outdoor light transformer? It it
doesn't, then you can pretty much conclude that it is the Christmas tree
lights specifically causing the problem. It would seem an incompatibility
between the outdoor lighting transformer and the particular Christmas tree
lights that you're using. There are many different types of both the
outdoor transformers and Christmas tree lights. The reasons the problem
might occur might be myriad, and not really worth the time you're wasting
on it, since it's doubtful you'll resolve it.

One consideration is that the string(s) of Christmas tree lights are
generating some type of frequency that reacts with the transformer, which
doesn't occur when a single light bulb is plugged in.

OTOH, if plugging anything else into this outlet also causes the problem,
then it's a problem that should definitely be investigated and resolved.

By the time you've explored all the possibilities, Christmas and perhaps
even New Year's will be over and it will be a moot point until next year.
:-)

--
Wayne Boatwright
(correct the spelling of "geemail" to reply)
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Date: Friday, 12(XII)/26(XXVI)/08(MMVIII)
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