[Jim Beaver]

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

[Ed Pawlowski]

"Jim Beaver" wrote in message

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'd say it is probably a harmonic vibration. How hard is it to disconnect
the timer? Just take one wire off.

Merry Christmas to you also.

[Jim Beaver]

"Ed Pawlowski" wrote in message
...

"Jim Beaver" wrote in message

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'd say it is probably a harmonic vibration. How hard is it to disconnect
the timer? Just take one wire off.

I can unplug it. But it's outside in the rain, so I've been nervous. Also,
doing so deletes the various sector sprinkler timing, a nuisance even bigger
than the hum...IF the hum is safe.

Thanks.

Jim Beaver

[E Z Peaces]

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.

If letting it hum damaged the system, wouldn't that be more trouble than
reprogramming the timer?

You could kill the power at the breaker box before unplugging it, but
unplugging it in the rain probably isn't dangerous. In the days when
footwear had leather soles that could be salty from sweat, 110V could be
very dangerous if you stood on a wet surface. Synthetic soles seem to
offer better protection.

A tingle is possible with rubber footwear. At the farm, my sister would
get a tingle each morning at dawn when she unplugged a light from an
outdoor extension cord, although she wore rubber footwear. By the time
her husband woke up, the grass and cord would be dry, and he'd tell her
there was nothing wrong. The only defect I found was mildew which, when
damp, could carry enough current for a tingle. Washing the ends of the
cords cured the problem. He happened to be right that it wasn't
dangerous. She was right that it should not have been ignored.

[HeyBub[_3_]]

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

Extension cord to a different circuit.

[Jim Beaver]

"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

[E Z Peaces]

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.

[Wayne Boatwright[_5_]]

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?

--
Wayne Boatwright
(correct the spelling of "geemail" to reply)
************************************************** **********************
Date: Thursday, 12(XII)/25(XXV)/08(MMVIII)
************************************************** **********************
Today is: Christmas
Countdown till New Year's Eve
5dys 3hrs 23mins
************************************************** **********************
Heute die Welt, Morgens das Sonnensystem!
************************************************** **********************

[E Z Peaces]

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.

[Jim Beaver]

"Wayne Boatwright" wrote in message
5.247...
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?

Hate puzzles. Just trying to avoid running a twenty-foot extension cord to
the nearest receptacle not on this circuit. Christmas is dangerous enough
without decking cables down and across my halls. Also, I find a house
without extension cords running across major thoroughfares to be more
elegant than one with such obstacles.

Jim Beaver

[Wayne Boatwright[_5_]]

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)
************************************************** **********************
Date: Friday, 12(XII)/26(XXVI)/08(MMVIII)
************************************************** **********************
Today is: Boxing Day (U.K.)
Countdown till New Year's Eve
4dys 23hrs 48mins
************************************************** **********************
Oxymoron: Sugarless Candy.
************************************************** **********************

[Wayne Boatwright[_5_]]

On Fri 26 Dec 2008 12:21:58a, Jim Beaver told us...


"Wayne Boatwright" wrote in message
5.247...
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?

Hate puzzles. Just trying to avoid running a twenty-foot extension cord
to the nearest receptacle not on this circuit. Christmas is dangerous
enough without decking cables down and across my halls. Also, I find a
house without extension cords running across major thoroughfares to be
more elegant than one with such obstacles.

Jim Beaver



Well, I really can't disagree with that. I have no clue why this is
happening. I assume when you plug anything else other than the Christmas
tree lights into this socket that it doesn't cause the problem. If that's
true, it may be that the string(s) of light on the tree are generating some
sort of frequency that's being picked up by the transformer. Actually,
transformers usually generate a hum most of the time, even if relatively
inaudible. Consider that the transformer generates a magnetic field and
may be oscillating because of the frequency that may be generated by the
multple miniature lights. Many things are possible. I doubt seriously
that this situation is actually dangerous.

--
Wayne Boatwright
(correct the spelling of "geemail" to reply)
************************************************** **********************
Date: Friday, 12(XII)/26(XXVI)/08(MMVIII)
************************************************** **********************
Today is: Boxing Day (U.K.)
Countdown till New Year's Eve
4dys 23hrs 27mins
************************************************** **********************
Shotgun wedding: a case of wife or death.
************************************************** **********************

[E Z Peaces]

Jim Beaver wrote:

"Wayne Boatwright" wrote in message
5.247...
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?

Hate puzzles. Just trying to avoid running a twenty-foot extension cord
to the nearest receptacle not on this circuit. Christmas is dangerous
enough without decking cables down and across my halls. Also, I find a
house without extension cords running across major thoroughfares to be
more elegant than one with such obstacles.

Jim Beaver

How do the outdoor lights come on? If it's not a timer or a manual
switch, it must be a light sensor.

Incandescent Christmas lights don't generate frequencies, and
"frequencies" shouldn't make a transformer hum. Incandescent Christmas
lights generate light, and light can make a light sensor turn lights off
and on. If you hear a hum, it's probably too fast to see flickering.
The solution would be to shield the sensor from artificial light.

[Wayne Boatwright[_5_]]

On Fri 26 Dec 2008 01:48:54a, E Z Peaces told us...

Jim Beaver wrote:

"Wayne Boatwright" wrote in message
5.247...
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?

Hate puzzles. Just trying to avoid running a twenty-foot extension cord
to the nearest receptacle not on this circuit. Christmas is dangerous
enough without decking cables down and across my halls. Also, I find a
house without extension cords running across major thoroughfares to be
more elegant than one with such obstacles.

Jim Beaver

How do the outdoor lights come on? If it's not a timer or a manual
switch, it must be a light sensor.

Incandescent Christmas lights don't generate frequencies, and
"frequencies" shouldn't make a transformer hum. Incandescent Christmas
lights generate light, and light can make a light sensor turn lights off
and on. If you hear a hum, it's probably too fast to see flickering.
The solution would be to shield the sensor from artificial light.


There are too many unanswered questions for me. First, not all Christmas
tree lights are incandescent; some are LEDs. Second, if the outdoor lights
are powered by a transformer and triggered by a light sensor, it seems
unlikely that an indoor Christmas tree could interfere with its function.
If the outdoor lights are interfering, then it would happen irrespective of
the Christmas tree.

--
Wayne Boatwright
(correct the spelling of "geemail" to reply)
************************************************** **********************
Date: Friday, 12(XII)/26(XXVI)/08(MMVIII)
************************************************** **********************
Today is: Boxing Day (U.K.)
Countdown till New Year's Eve
4dys 21hrs 58mins
************************************************** **********************
California raisins murdered: Cereal Killer suspected
************************************************** **********************

[Ed Pawlowski]

"Wayne Boatwright" wrote in message
There are too many unanswered questions for me. First, not all Christmas
tree lights are incandescent; some are LEDs. Second, if the outdoor
lights
are powered by a transformer and triggered by a light sensor, it seems
unlikely that an indoor Christmas tree could interfere with its function.
If the outdoor lights are interfering, then it would happen irrespective
of
the Christmas tree.

--
Wayne Boatwright


There may be some other factor that we are not aware of. Such as an X-10
control or an intercom systems that plugs in, or some other transformer or
control on the same circuit. Tree lights also have series wiring in some
cases too. We now know of the transformer for the outdoor lights. That, I
suspect, is doing something funky.

[[email protected]]

Just thinking out loud:

Overloading the timer, what is it's rated capacity and what
is the total load?

Bad neutral problem?

Is this on a Ground Fault circuit?

[E Z Peaces]

Wayne Boatwright wrote:
On Fri 26 Dec 2008 01:48:54a, E Z Peaces told us...

Jim Beaver wrote:
"Wayne Boatwright" wrote in message
5.247...
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?
Hate puzzles. Just trying to avoid running a twenty-foot extension cord
to the nearest receptacle not on this circuit. Christmas is dangerous
enough without decking cables down and across my halls. Also, I find a
house without extension cords running across major thoroughfares to be
more elegant than one with such obstacles.

Jim Beaver
How do the outdoor lights come on? If it's not a timer or a manual
switch, it must be a light sensor.

Incandescent Christmas lights don't generate frequencies, and
"frequencies" shouldn't make a transformer hum. Incandescent Christmas
lights generate light, and light can make a light sensor turn lights off
and on. If you hear a hum, it's probably too fast to see flickering.
The solution would be to shield the sensor from artificial light.


There are too many unanswered questions for me. First, not all Christmas
tree lights are incandescent; some are LEDs. Second, if the outdoor lights
are powered by a transformer and triggered by a light sensor, it seems
unlikely that an indoor Christmas tree could interfere with its function.
If the outdoor lights are interfering, then it would happen irrespective of
the Christmas tree.


The original post seemed to answer your questions about the tree lights.
People like to put Christmas trees in front windows.

Outdoor lighting systems often have a sensor on the timer. Typically,
the sensor turns it on at dusk and the timer turns it off.

Instructions warn the homeowner that ambient light can make the system
cycle. Yard lights are often aimed at the house and sensor, so the
sensor's threshold may be adjustable.

If plugging in the tree lights makes the outdoor system noisy, I think
ambient light from the tree raises the level at the sensor above the
shut-off threshold. The light could come straight from the tree, or it
could reflect off something outside. When the sensor switches the
outdoor lights off, that may reduce the light on the sensor, which would
then switch the lights back on. The flicker of the outdoor lights may
not be conspicuous.

I think the racket comes from relay chatter. If the timer is designed
for 300 watts of 12V lights, a relay would have to work with a 200A
starting surge. I think a relay that big could be heard indoors.

[Jim Beaver]

"E Z Peaces" wrote in message
.. .
Wayne Boatwright wrote:
On Fri 26 Dec 2008 01:48:54a, E Z Peaces told us...

Jim Beaver wrote:
"Wayne Boatwright" wrote in message
5.247...
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?
Hate puzzles. Just trying to avoid running a twenty-foot extension
cord to the nearest receptacle not on this circuit. Christmas is
dangerous enough without decking cables down and across my halls.
Also, I find a house without extension cords running across major
thoroughfares to be more elegant than one with such obstacles.

Jim Beaver
How do the outdoor lights come on? If it's not a timer or a manual
switch, it must be a light sensor.

Incandescent Christmas lights don't generate frequencies, and
"frequencies" shouldn't make a transformer hum. Incandescent Christmas
lights generate light, and light can make a light sensor turn lights off
and on. If you hear a hum, it's probably too fast to see flickering.
The solution would be to shield the sensor from artificial light.


There are too many unanswered questions for me. First, not all Christmas
tree lights are incandescent; some are LEDs. Second, if the outdoor
lights are powered by a transformer and triggered by a light sensor, it
seems unlikely that an indoor Christmas tree could interfere with its
function. If the outdoor lights are interfering, then it would happen
irrespective of the Christmas tree.


The original post seemed to answer your questions about the tree lights.
People like to put Christmas trees in front windows.

Outdoor lighting systems often have a sensor on the timer. Typically, the
sensor turns it on at dusk and the timer turns it off.

Instructions warn the homeowner that ambient light can make the system
cycle. Yard lights are often aimed at the house and sensor, so the
sensor's threshold may be adjustable.

If plugging in the tree lights makes the outdoor system noisy, I think
ambient light from the tree raises the level at the sensor above the
shut-off threshold. The light could come straight from the tree, or it
could reflect off something outside. When the sensor switches the outdoor
lights off, that may reduce the light on the sensor, which would then
switch the lights back on. The flicker of the outdoor lights may not be
conspicuous.

I think the racket comes from relay chatter. If the timer is designed for
300 watts of 12V lights, a relay would have to work with a 200A starting
surge. I think a relay that big could be heard indoors.

Okay. A few facts, which may help.

The low-voltage yard lighting is on a timer, not a light sensor. Even if it
were on a light sensor, the ambient light from the Christmas tree would have
no effect, as the tree is nowhere near a window and the windows are covered.
From outdoors it's impossible to tell whether the tree is lit or even
whether the normal room lights are on.

The tree lights are on two strings. Each string plugs in to a separate
socket (but in a single receptacle). Now here's where it gets interesting.
Only one of the strings makes the hum happen. When both are plugged in and
turned on the hum is loudest. But one of the strings can be turned off or
unplugged and there is still a hum. When the strings are reversed, i.e.,
the opposite string is turned off or unplugged, there is no hum.

The lights are incandescent, not LEDs, as far as I can tell. They're those
familiar glass teardrop-shaped bulbs, painted on the inside. The filaments
are not visible.

At this point, it's not a vital inquiry. The tree is coming down today or
tomorrow. But my curiosity is quite piqued, especially in light of some of
the information I've gathered here.

Thanks.

Jim Beaver

[Wayne Boatwright[_5_]]

On Fri 26 Dec 2008 02:11:34p, Jim Beaver told us...


"E Z Peaces" wrote in message
.. .
Wayne Boatwright wrote:
On Fri 26 Dec 2008 01:48:54a, E Z Peaces told us...

Jim Beaver wrote:
"Wayne Boatwright" wrote in message
5.247...
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?
Hate puzzles. Just trying to avoid running a twenty-foot extension
cord to the nearest receptacle not on this circuit. Christmas is
dangerous enough without decking cables down and across my halls.
Also, I find a house without extension cords running across major
thoroughfares to be more elegant than one with such obstacles.

Jim Beaver
How do the outdoor lights come on? If it's not a timer or a manual
switch, it must be a light sensor.

Incandescent Christmas lights don't generate frequencies, and
"frequencies" shouldn't make a transformer hum. Incandescent
Christmas lights generate light, and light can make a light sensor
turn lights off and on. If you hear a hum, it's probably too fast to
see flickering. The solution would be to shield the sensor from
artificial light.


There are too many unanswered questions for me. First, not all
Christmas tree lights are incandescent; some are LEDs. Second, if the
outdoor lights are powered by a transformer and triggered by a light
sensor, it seems unlikely that an indoor Christmas tree could
interfere with its function. If the outdoor lights are interfering,
then it would happen irrespective of the Christmas tree.


The original post seemed to answer your questions about the tree
lights. People like to put Christmas trees in front windows.

Outdoor lighting systems often have a sensor on the timer. Typically,
the sensor turns it on at dusk and the timer turns it off.

Instructions warn the homeowner that ambient light can make the system
cycle. Yard lights are often aimed at the house and sensor, so the
sensor's threshold may be adjustable.

If plugging in the tree lights makes the outdoor system noisy, I think
ambient light from the tree raises the level at the sensor above the
shut-off threshold. The light could come straight from the tree, or it
could reflect off something outside. When the sensor switches the
outdoor lights off, that may reduce the light on the sensor, which
would then switch the lights back on. The flicker of the outdoor
lights may not be conspicuous.

I think the racket comes from relay chatter. If the timer is designed
for 300 watts of 12V lights, a relay would have to work with a 200A
starting surge. I think a relay that big could be heard indoors.

Okay. A few facts, which may help.

The low-voltage yard lighting is on a timer, not a light sensor. Even
if it were on a light sensor, the ambient light from the Christmas tree
would have no effect, as the tree is nowhere near a window and the
windows are covered. From outdoors it's impossible to tell whether the
tree is lit or even whether the normal room lights are on.

The tree lights are on two strings. Each string plugs in to a separate
socket (but in a single receptacle). Now here's where it gets
interesting. Only one of the strings makes the hum happen. When both
are plugged in and turned on the hum is loudest. But one of the strings
can be turned off or unplugged and there is still a hum. When the
strings are reversed, i.e., the opposite string is turned off or
unplugged, there is no hum.

The lights are incandescent, not LEDs, as far as I can tell. They're
those familiar glass teardrop-shaped bulbs, painted on the inside. The
filaments are not visible.

At this point, it's not a vital inquiry. The tree is coming down today
or tomorrow. But my curiosity is quite piqued, especially in light of
some of the information I've gathered here.

Thanks.

Jim Beaver



Then, if I'm reading this right, one string does cause the problem, but the
other one (or the two together) does cause the problem. Obviously there's
something wrong with the one string of lights.

When you take the tree down, throw the bad string away. No problem. :-)

--
Wayne Boatwright
(correct the spelling of "geemail" to reply)
************************************************** **********************
Date: Friday, 12(XII)/26(XXVI)/08(MMVIII)
************************************************** **********************
Today is: Boxing Day (U.K.)
Countdown till New Year's Eve
4dys 8hrs 37mins
************************************************** **********************
Do fish get thirsty?
************************************************** **********************

[E Z Peaces]

Jim Beaver wrote:

"E Z Peaces" wrote in message
.. .
Wayne Boatwright wrote:
On Fri 26 Dec 2008 01:48:54a, E Z Peaces told us...

Jim Beaver wrote:
"Wayne Boatwright" wrote in message
5.247...
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?
Hate puzzles. Just trying to avoid running a twenty-foot extension
cord to the nearest receptacle not on this circuit. Christmas is
dangerous enough without decking cables down and across my halls.
Also, I find a house without extension cords running across major
thoroughfares to be more elegant than one with such obstacles.

Jim Beaver
How do the outdoor lights come on? If it's not a timer or a manual
switch, it must be a light sensor.

Incandescent Christmas lights don't generate frequencies, and
"frequencies" shouldn't make a transformer hum. Incandescent
Christmas lights generate light, and light can make a light sensor
turn lights off and on. If you hear a hum, it's probably too fast
to see flickering. The solution would be to shield the sensor from
artificial light.


There are too many unanswered questions for me. First, not all
Christmas tree lights are incandescent; some are LEDs. Second, if
the outdoor lights are powered by a transformer and triggered by a
light sensor, it seems unlikely that an indoor Christmas tree could
interfere with its function. If the outdoor lights are interfering,
then it would happen irrespective of the Christmas tree.


The original post seemed to answer your questions about the tree
lights. People like to put Christmas trees in front windows.

Outdoor lighting systems often have a sensor on the timer. Typically,
the sensor turns it on at dusk and the timer turns it off.

Instructions warn the homeowner that ambient light can make the system
cycle. Yard lights are often aimed at the house and sensor, so the
sensor's threshold may be adjustable.

If plugging in the tree lights makes the outdoor system noisy, I think
ambient light from the tree raises the level at the sensor above the
shut-off threshold. The light could come straight from the tree, or
it could reflect off something outside. When the sensor switches the
outdoor lights off, that may reduce the light on the sensor, which
would then switch the lights back on. The flicker of the outdoor
lights may not be conspicuous.

I think the racket comes from relay chatter. If the timer is designed
for 300 watts of 12V lights, a relay would have to work with a 200A
starting surge. I think a relay that big could be heard indoors.

Okay. A few facts, which may help.

The low-voltage yard lighting is on a timer, not a light sensor. Even
if it were on a light sensor, the ambient light from the Christmas tree
would have no effect, as the tree is nowhere near a window and the
windows are covered. From outdoors it's impossible to tell whether the
tree is lit or even whether the normal room lights are on.

The tree lights are on two strings. Each string plugs in to a separate
socket (but in a single receptacle). Now here's where it gets
interesting. Only one of the strings makes the hum happen. When both
are plugged in and turned on the hum is loudest. But one of the strings
can be turned off or unplugged and there is still a hum. When the
strings are reversed, i.e., the opposite string is turned off or
unplugged, there is no hum.

The lights are incandescent, not LEDs, as far as I can tell. They're
those familiar glass teardrop-shaped bulbs, painted on the inside. The
filaments are not visible.

At this point, it's not a vital inquiry. The tree is coming down today
or tomorrow. But my curiosity is quite piqued, especially in light of
some of the information I've gathered here.

Thanks.

Jim Beaver

I wonder if electrical noise is affecting an electronic switch or dimmer
controlling the outdoor lights. An AM radio might detect noise coming
from the Christmas lights. I used to walk along an electric fence with
an AM radio to find leaky insulators.