Ideas needed - rotating display inside lighting

[arnoldus]

Hello,

I am responsible for a little statue on an exposition, which needs interior lighting. The idea is that the light should come out of several holes on the statuette, and illuminate nearby walls (it's going to be a dimly lit room), kind of like a disco ball effect. The big problem is that the object is on a turntable and spins around, so solutions with a powersupply are hard to construct as the wires would tangle. We have tried with a Fenix L2D flashlight, which has the approx required light strenght, but the light is too focused, it does not scatter enough in the short distance of the statuette to illuminate from the sides. I have tried to use a cone made of paper to diffuse the light, but then there's not enough light to illuminate the walls at all.

I wonder if you have any good idea's that could help me out. These are the requirements:

-should fit in about 5cmx10cm (2*4inch) (inside space in statue)
-should output at least 100lum, and scatter the light
-should be battery powered and last at least 4hours.

 

[datiLED]

That sounds like an interesting display you are working on. You could probably get away with using an array of 5mm, or 10mm LED's. You could do direct drive with a resistor for each LED (in parallel), or take a more elegant approach and use a driver built from something like an OnSemi CAT4238. It will drive a string of 10 LED's in series at a constant current from a single LiIon cell, or three 1.5V batteries. Two strings of 10 LED's each would yield a bright display in a dim room. It would be much brighter than you think!

The 10mm LED's are very focused, and would project a beam better than the 5mm variety.

 

[PhotonWrangler]

One way to accomplish this is with a rotary transformer, where the primary winding is static and the secondary rotates inside of the primary.

VCRs use very low current rotary transformers in the video head assembly to couple the video signal to/from the spinning record/playback heads. If you can find a higher current version of this (or hack an existing video drum assembly), you can build a small rectifier circuit inside the rotating portion of the statue, maybe hidden inside a puck at the base, to drive the LEDs. You'll also need to modify the motor assembly as I'm sure you don't want the statue to spin at several thousand rpm.