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I wanted to know if it would be physically possible to run LEDs off of some sort of transmitting device, wirelessly? It's important I be able to use extremely small LEDs and have the smallest possible parts connected to the LEDs to use them in the spaces I would like.

I would like to be able to operate the LED up to a few feet away so it's not limited to being within just an inch or two of the transmitter.

The other thing I've noticed on some of the online videos is the coil that is connected to the LED is quite large. Ideally, I'm trying to get both the LED and whatever is necessary for the receiver component to fit within a 5mm W x 7mm H cylinder. Obviously, quite small.

Can this be done?

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What is the distance between the transmitter and the LED. – Bruno Ferreira Jul 19 '12 at 19:03
Thanks for moving the answer update over @russellMcMahon, you did well, you may have been able to vote to delete the useless answer yourself(?) and flag as not an answer so other 10k + users would see it and help vote to delete(no diamond mod needed!). Thanks for the work. – Kortuk♦ Jul 20 '12 at 3:30
Can you tell us what you want to do with the LEDs? – starblue Jul 23 '12 at 5:51
I simply want the LEDs to be either on or off - just a constant light, until I wanted to turn it off. They would be used as part of a display/diorama. – Dustin C Jul 23 '12 at 11:17

2 Answers

up vote 5 down vote

It is possible to power LED wirelessly, and the process is quite simple.

  • For the receiver, you just need to build a coil and connect it to a LED.

  • For the transmitter, you'll need another coil. This one is powered by an AC voltage.

In order to work, the LED's coil must be prependicular with the magnetic field created by the transmitter.

You can think of this as transformer where you replace the core with air. The transmitter is the primary of the transformmer and the receiver is the secundary.

You can see the explanation in this video.

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Any additional input on this? I'm on a tight timeline to see if this can be accomplished... :) – Dustin C Jul 23 '12 at 18:03
up vote 1 down vote

I would like to be able to operate the LED up to a few feet away so it's not limited to being within just an inch or two of the transmitter.

The other thing I've noticed on some of the online videos is the coil that is connected to the LED is quite large. Ideally, I'm trying to get both the LED and whatever is necessary for the receiver component to fit within a 5mm W x 7mm H cylinder. Obviously, quite small. Can this be done?

Transmission range using a magnetic field is dependant on field strength and the Q of the receive coil. Using a 5mm dia coil and achieving a range of say 500mm is extremely difficult. It MAY be possible with immense receive q factor but this would require very special tuning capability.

You may be better using microwave and RF Unfortunately, at the dimensions you mention you'd need to be at 10's of GHz for the receiver aerial to approach 1 wavelength, which you'd probably need. Maybe doable but very hard.

You do not say what power level you want or how long you want them to operate for. Battery powering may be an option.

LASER optical powering may be an option.

If you better described the application you may get a better answer.
eg IF it was possible to operate the target inside a large cube whose sides extend beyond the target then you would find wireless power transfer much easier. eg a 1 metre edge cube with wires along the edges can allow power transfer into a coil of the sie you need in many locations inside the cube.

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