Phantom Voltage?

[meburdick]

I have a light switch that controls a couple of wall-mounted sconces as well as a single outlet. I figured out that the outlet was part of the circuit when I went to plug a UPS device into it and it wouldn't show line voltage until I flipped the switch. Ok, no problem... I moved the UPS to a non-switched outlet and decided I would add lighting by plugging a lamp into this outlet.

When I plugged the lamp in, the bulb immediately lit. I was surprised as I didn't realize I had the switch on. Turns out, I -didn't- have the switch on! I pulled out the digital multi-meter and started checking for AC voltage and discovered that I'm seeing the full 120V when the switch is on, but I'm seeing a very low amount of voltage (2-3VAC) when it's off. Turning the breaker off drops it down to "basically" zero (.002VAC or similar).

I fully removed the outlet and can verify that it is the end of the circuit and voltage on the wires measures identical to probing the outlet itself.

This is a very small lamp, with a very small LED bulb in it. Although the voltage is very low, it's enough to partially illuminate the bulb (the light output increases with the switch on). While it very well may be "just" phantom voltage from a close-by circuit, I'm wondering if anyone has any ideas of how to easily track it down and correct it. I do not know if the wiring heads down toward the floor below or up towards the attic (yet) - there is some AC in the attic space, but I haven't yet had the opportunity to start tracing it. And, if this wiring -doesn't- go into the attic, I'm going to be at a complete loss to be able to track it down.

Just looking for tips before I bring in an electrician to figure it out.

 

[Shiftless]

So the switched receptacle is on the same circuit as the 2 wall sconces, right?
I assume the wall sconce lamps don’t glow when the switch is off.
I would just use the same bulb in your portable lamp as in the wall sconces and go from there.
If you want additional light from the table lamp, what is up with the very small lamp with very small LED bulb? How small is very small? Go ahead and spend money on an electrician, but from what you said, I don’t think you have a problem.

 

[meburdick]

So the switched receptacle is on the same circuit as the 2 wall sconces, right?
I assume the wall sconce lamps don’t glow when the switch is off.
I would just use the same bulb in your portable lamp as in the wall sconces and go from there.
If you want additional light from the table lamp, what is up with the very small lamp with very small LED bulb? How small is very small? Go ahead and spend money on an electrician, but from what you said, I don’t think you have a problem.

Yes, your assumptions about sconces NOT being lit are correct (a small detail that I left out, but a useful one just the same).

The sconces light one side of the room, the small lamp I am hoping to connect up would light the other. This isn't a space that needs to be "well it", just lit when the sun is down... It very well could be the bulb as I believe I have been able to get this to light by (I kid you not) touching the plug prongs to a couple of sockets (as in mechanic tools) lying on a piece of cloth!

 

[Gozo]

What kind of bulb is that? It would be useful during power outages. I could put a few of my 10mm sockets and a few rags out and stop searching for a flashlight with good batteries.
I’ve not encountered phantom voltages aside from a few millivolts from inductive coupling.

 

[meburdick]

What kind of bulb is that? It would be useful during power outages. I could put a few of my 10mm sockets and a few rags out and stop searching for a flashlight with good batteries.
I’ve not encountered phantom voltages aside from a few millivolts from inductive coupling.

Sounds really weird, right? It's branded as the in-house brand from a big, blue retailer...

Check this out - a little pressure from the weight of the base to touch the prongs against the shaft of this screwdriver:

 

[meburdick]

Here's the pic...

 

[Zeke]

Often times you will get inductive voltage on a wire from other wires. 2-3 volts seems about right to me. You can also have a wiring problem. Most wiring issues are and can be corrected at boxes. To find out about inductive voltage you will have to kill any circuits at that part of the house except the one that has the phantom. If it goes away, then you may or may not be able to do anything about it depending on the source. So, turn the breakers back on one by one until you see the PV again and see if you can trace that and the PV circuits back to the panel. I'd open up every device along the way just to check.

 

[Firebrick43]

I have seen phantom voltages in long runs of industrial CNC machines. Its always a wires run parrall to others. Most of the impertant signal wires have a woven shield that is terminated at the ground plane to prevent this. Another trick was to tightly twist pairs of wire.

But I have seen stray voltages in unshielded wires. I have also seen it in high tensile electric fence, where one un energized wire has some shock to it because it parallel the energized one for a really long difference.

The easiest way to deal with it is a choke. A ferrite bead choke would be my starting point as they are very easy to install and normally clean up the noise.

 

[PCustoms]

Here's the pic...

Wait, WTF?

Am I seeing this correctly, the lamp is powering itself?

That's one of those battery backup bulbs

 

[meburdick]

Wait, WTF?

Am I seeing this correctly, the lamp is powering itself?

That's one of those battery backup bulbs

lol... It is absolutely NOT a battery backup bulb. It is a 5W LED from Wally World. It's the strangest thing I've ever come across.

If I remove the screwdriver or ease the pressure up slightly that the base is pressing down on it with, it goes off and stays off.

 

[PCustoms]

Residual voltage in the LED driver circuit. Somehow shorting across the plug completes a circuit.

Either that or ghosts. Maybe call Ghostbusters or an electrician?

 

[meburdick]

Residual voltage in the LED driver circuit. Somehow shorting across the plug completes a circuit.

Either that or ghosts. Maybe call Ghostbusters or an electrician?

lol... Ghost Busters FTW!

I don't believe it's residual voltage because it will seemingly stay lit indefinitely. I would expect that it would draw down any residual in a matter of a minute or two, but it doesn't even dim.

 

[PCustoms]

If that's not a residual voltage you've got some serious (inductive? Induction? Potential? Idk) Voltage oddities nearby.

High voltage power line over the house?

Does your Tesla self charge in the driveway?

 

[meburdick]

If that's not a residual voltage you've got some serious (inductive? Induction? Potential? Idk) Voltage oddities nearby.

High voltage power line over the house?

Does your Tesla self charge in the driveway?

Did it at the last house, too. Very strange, indeed - I've basically chalked it up to it being such a low wattage bulb.

 

[Gozo]

Wait, WTF?

Am I seeing this correctly, the lamp is powering itself?

That's one of those battery backup bulbs

Yup. Definitely one for the WTF thread. Hence my ask what type of bulbs they are.
I got lamps, blankets, and screwdrivers here. Free lighting! I’m in for that.

Seriously, if you’ve got that much stray EMF floating around the house, there’s something weird and/or dangerous going on. They use electromagnetic fields for all sorts of therapeutic brain stimulation. Maybe you should bill your HMO.

I’m gonna pick up one at the blue box store and see if get lucky.

 

[walta]

Let’s talk about the switches in your walls any chance they have a light inside the switch that lights up when the switch is turned off? Or are they the silent ones with the mercury bulbs instead of contacts?

Is the table lamp one of the ones you operate by touching a metal part?

Would there be a dusk to dawn sensor on this circuit?

Any of these devices would leak enough current to light your LED.



Walta

 

[PCustoms]

Let’s talk about the switches in your walls any chance they have a light inside the switch that lights up when the switch is turned off? Or are they the silent ones with the mercury bulbs instead of contacts?

Is the table lamp one of the ones you operate by touching a metal part?

Would there be a dusk to dawn sensor on this circuit?

Any of these devices would leak enough current to light your LED.



Walta

Look closely at his picture.....

It's not even plugged in.

We are being trolled.

 

[meburdick]

Let’s talk about the switches in your walls any chance they have a light inside the switch that lights up when the switch is turned off? Or are they the silent ones with the mercury bulbs instead of contacts?

Is the table lamp one of the ones you operate by touching a metal part?

Would there be a dusk to dawn sensor on this circuit?

Any of these devices would leak enough current to light your LED.



Walta

Basic SPST switch. No light in it, the lamp has the typical rotating switch you would expect in a "table lamp". No sensors.

I changed from the 5W LED bulb to a 10.5W LED bulb and it works 100% as expected.

 

[meburdick]

Look closely at his picture.....

It's not even plugged in.

We are being trolled.

I swear I'm not trolling with this - it's 100% legit. I have honestly never seen anything like it. I have absolutely no idea where/how it's picking up energy to partially illuminate (it isn't full brightness) that bulb simply by pressing a conductor across the prongs of the plug.

I discovered that this lamp/bulb did this a couple of years ago completely by accident. As I had mentioned, the plug came into contact with a mechanic's socket and the bulb turned on (the lamp switch was on). I totally forgot about that until I started trying to understand what was happening here and I remembered that I had discovered this in our last house.

 

[PCustoms]

I swear I'm not trolling with this - it's 100% legit. I have honestly never seen anything like it. I have absolutely no idea where/how it's picking up energy to partially illuminate (it isn't full brightness) that bulb simply by pressing a conductor across the prongs of the plug.

I discovered that this lamp/bulb did this a couple of years ago completely by accident. As I had mentioned, the plug came into contact with a mechanic's socket and the bulb turned on (the lamp switch was on). I totally forgot about that until I started trying to understand what was happening here and I remembered that I had discovered this in our last house.

So your lamp is possessed and is self powered.

Moving on, what questions did you have about the wiring in your house?

 

[walta]

I swear I'm not trolling with this - it's 100% legit. I have honestly never seen anything like it. I have absolutely no idea where/how it's picking up energy to partially illuminate (it isn't full brightness) that bulb simply by pressing a conductor across the prongs of the plug.

I discovered that this lamp/bulb did this a couple of years ago completely by accident. As I had mentioned, the plug came into contact with a mechanic's socket and the bulb turned on (the lamp switch was on). I totally forgot about that until I started trying to understand what was happening here and I remembered that I had discovered this in our last house.

I tend to believe you did not join GJ with a plan to start trolling after 11 years and 200 posting to gain our confidence.

So, help us understand this photo you posted showing the bulb lit while unplugged.

 

[meburdick]

I tend to believe you did not join GJ with a plan to start trolling after 11 years and 200 posting to gain our confidence.

So, help us understand this photo you posted showing the bulb lit while unplugged.

I mean... I could be playing the really long con here.

The only thing that I can think of is that the components are capable of illuminating from very small current and voltage amounts. Here are two more pics of -just- the bulb... I'm just holding it in my hand loosely in the one where it isn't lit and then I press my fingers harder against the contacts to get it to light. If someone can tell me how to post a video, I'll happily do it...

 

[Milton Shaw]

Moisture/water will cause some voltage problems you are describing. Check to see if anything is catching water. Seen this in refrigerator wiring and other places where moisture will form from environment.

 

[wyliesdiesels]

photoshop?

 

[rockettauto]

That is a battery backup bulb whether you realized it or not. Sorry, nothing crazy to see here. Here's the backup design.
Note the globe is basically a dome on top and vents on side. It lights when you press the contacts because it's detecting that it is screwed in and has no power.

Coolest part actually is that I believe that means it emits a tiny rf toner signal or essentially the same inductive proximity circuitry as a touch lamp except that once its plugged in to wiring the " antenna" is long enough to trigger itself. That's why it lights when you short the plug or when it has a long enough pair of wire connected to it. Thats likely the voltage you're picking up on the meter when it's plugged in



Versus their typical bulb.....also they don't have a 5w standard, just 5.5 and 6. Note the full globe.

 

[PCustoms]

That is a battery backup bulb whether you realized it or not. Sorry, nothing crazy to see here. Here's the backup design.
Note the globe is basically a dome on top and vents on side. It lights when you press the contacts because it's detecting that it is screwed in and has no power.

Coolest part actually is that I believe that means it emits a tiny rf toner signal or essentially the same inductive proximity circuitry as a touch lamp except that once its plugged in to wiring the " antenna" is long enough to trigger itself. That's why it lights when you short the plug or when it has a long enough pair of wire connected to it. Thats likely the voltage you're picking up on the meter when it's plugged in



Versus their typical bulb.....also they don't have a 5w standard, just 5.5 and 6. Note the full globe.

So, RTFM?

 

[rockettauto]

So, RTFM?

Hell, just the package will suffice.


New trick to play on the kids though.

 

[scooby074]

I mean... I could be playing the really long con here.

The only thing that I can think of is that the components are capable of illuminating from very small current and voltage amounts. Here are two more pics of -just- the bulb... I'm just holding it in my hand loosely in the one where it isn't lit and then I press my fingers harder against the contacts to get it to light. If someone can tell me how to post a video, I'll happily do it...

Are you Uncle Fester?

 

[meburdick]

That is a battery backup bulb whether you realized it or not. Sorry, nothing crazy to see here. Here's the backup design.
Note the globe is basically a dome on top and vents on side. It lights when you press the contacts because it's detecting that it is screwed in and has no power.

Coolest part actually is that I believe that means it emits a tiny rf toner signal or essentially the same inductive proximity circuitry as a touch lamp except that once its plugged in to wiring the " antenna" is long enough to trigger itself. That's why it lights when you short the plug or when it has a long enough pair of wire connected to it. Thats likely the voltage you're picking up on the meter when it's plugged in



Versus their typical bulb.....also they don't have a 5w standard, just 5.5 and 6. Note the full globe.

Hmmm. I will have to do some experimenting to see if the bulb will eventually "die" as the claim is that it should run for about 90 minutes. I would never have bought this type of bulb on purpose...

 

[meburdick]

Are you Uncle Fester?

You found me out! lol

 

[pancho400cid]

Welp... I learned something today.

 

[wyliesdiesels]

That is a battery backup bulb whether you realized it or not. Sorry, nothing crazy to see here. Here's the backup design.
Note the globe is basically a dome on top and vents on side. It lights when you press the contacts because it's detecting that it is screwed in and has no power.

Coolest part actually is that I believe that means it emits a tiny rf toner signal or essentially the same inductive proximity circuitry as a touch lamp except that once its plugged in to wiring the " antenna" is long enough to trigger itself. That's why it lights when you short the plug or when it has a long enough pair of wire connected to it. Thats likely the voltage you're picking up on the meter when it's plugged in



Versus their typical bulb.....also they don't have a 5w standard, just 5.5 and 6. Note the full globe.

wow never seen those before. mystery solved...

 

[wyliesdiesels]

Welp... I learned something today.

i did too.... wonder how much these cost

 

[Gozo]

Disappointment. No free lighting.
As far as learning something new, count me in that club. Never seen that before.

 

[BigGarage]

You found me out! lol

Fester could make it blink...can you?

 

[meburdick]

Fester could make it blink...can you?

I'd say that the answer is technically that I can, but I'm not putting a light bulb in my mouth.

 

[rockettauto]

i did too.... wonder how much these cost

About $6

 

[fitter30]

Check out this Amazon review of Lutron LUT-MLC

It's a simple capacitor and it works to eliminate LED ghosting

www.amazon.com

https://www.amazon.com/dp/B01E9F084E/?tag=atomicindus08-20

 

[kaffine]

Take the bulbs out of the scones and it should work like a normal light then.

It detects resistance between line and neutral to know the difference between being turned off and a power failure. If it is open between line and neutral it will turn off as it thinks it is powered of in purpose vs a power outage.

I should get one of these bulbs just to mess with people.