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Originally posted by maladat:

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Originally posted by sigcrazy7:

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Originally posted by kkina:
^Induction was my first thought as well, but the OP mentioned not being near high voltage lines. Would an ordinary stepped-down residential power line generate that much of a magnetic field I wonder?

As I stated above, residential distribution is 14,000 volts. That’s still significant voltage. Also, distribution lines are much lower.

This would be easy to test. Take a little coil of wire and put a meter on each side and check it for micro voltage.

Magnetic induction happens as a result of current, voltage is actually irrelevant.

There’s a separate phenomenon that can occur due to electric fields produced by high voltages, but I don’t think that it would cause an LED to light up near a residential distribution line.

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Originally posted by radioman:

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Originally posted by maladat:

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Originally posted by sigcrazy7:

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Originally posted by kkina:
^Induction was my first thought as well, but the OP mentioned not being near high voltage lines. Would an ordinary stepped-down residential power line generate that much of a magnetic field I wonder?

As I stated above, residential distribution is 14,000 volts. That’s still significant voltage. Also, distribution lines are much lower.

This would be easy to test. Take a little coil of wire and put a meter on each side and check it for micro voltage.

Magnetic induction happens as a result of current, voltage is actually irrelevant.

There’s a separate phenomenon that can occur due to electric fields produced by high voltages, but I don’t think that it would cause an LED to light up near a residential distribution line.

I see somebody studied Maxwell's Equations in college.

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Originally posted by Flash-LB:
Actually, magnetic induction produces voltage, not the other way around.

https://www.electronics-tutori...g%20just%20magnetism.

In other words, Electromagnetic Induction is the process of using magnetic fields to produce voltage, and in a closed circuit, a current.

So how much voltage (emf) can be induced into the coil using just magnetism. Well this is determined by the following 3 different factors.

1). Increasing the number of turns of wire in the coil – By increasing the amount of individual conductors cutting through the magnetic field, the amount of induced emf produced will be the sum of all the individual loops of the coil, so if there are 20 turns in the coil there will be 20 times more induced emf than in one piece of wire.

2). Increasing the speed of the relative motion between the coil and the magnet – If the same coil of wire passed through the same magnetic field but its speed or velocity is increased, the wire will cut the lines of flux at a faster rate so more induced emf would be produced.
3). Increasing the strength of the magnetic field – If the same coil of wire is moved at the same speed through a stronger magnetic field, there will be more emf produced because there are more lines of force to cut.

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Originally posted by sigcrazy7:

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Originally posted by kkina:
^Induction was my first thought as well, but the OP mentioned not being near high voltage lines. Would an ordinary stepped-down residential power line generate that much of a magnetic field I wonder?

As I stated above, residential distribution is 14,000 volts. That’s still significant voltage. Also, distribution lines are much lower.

This would be easy to test. Take a little coil of wire and put a meter on each side and check it for micro voltage.

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Easy test, pull the battery cable

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Originally posted by kkina:I

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Originally posted by selogic:
I hate to burst some of yall's bubble , but I spent most of my 40 yr career with power companies working in high voltage substations . The voltage in some of them was as much as 550,000 volts and the buswork was very low in some of them . Obviously we had LED's on vehicles , trailers , and tons of them on equipment indicating lights . I never saw an LED light up from induction , static , or anything else like that.

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Originally posted by kkina:
I've heard that fluorescent tubes can be illuminated in the proximity of high tension lines. So why not LEDs?

Induction happens when you move a conductor through a magnetic field. Electrons flow = current. In this case, the conductive circuit is stationary, and the magnetic field is moving, generated by the alternating current in the high voltage lines (same process as used by wireless phone chargers).

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Originally posted by Krazeehorse:
Didn't Tesla light his lab with fluorescent tubes that weren't "connected" to anything?

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Originally posted by radioman:

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Originally posted by selogic:
I hate to burst some of yall's bubble , but I spent most of my 40 yr career with power companies working in high voltage substations . The voltage in some of them was as much as 550,000 volts and the buswork was very low in some of them . Obviously we had LED's on vehicles , trailers , and tons of them on equipment indicating lights . I never saw an LED light up from induction , static , or anything else like that.

Yeah, I see what you mean. We've covered how the mag field from the current in power lines could send the power, but for the LED to light, the trailer end of things (LED, Etc.) would need a complete circuit for current to flow through the LED. Much like the secondary circuit on a transformer with weak coupling. I don't see that we have that necessary complete circuit loop, unless I missed something in how the trailer wiring was described. .

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Originally posted by selogic:
If 550,000 volts in close proximity to an LED won't turn it on , your distribution line sure won't do it . Believe what you want .

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Originally posted by maladat:

<snip>

However, it’s certainly possible in principle. There’s plenty of energy in the electromagnetic fields around power lines carrying a lot of current. The mechanism is different and doesn’t apply to LEDs, but as an example, you can go stand under transmission lines with a bare 4’ fluorescent tube that isn’t connected to anything and it will glow. It won’t “turn on” like it is plugged in, but it will glow enough that you can see it.