Lighting Lorcini

Since I was 7 years old this 1965 wall sculpture, "BETA BYG" by Gino Lorcini has been prominently displayed in my parent's home.  For perhaps the past decade, my father has asked me if it would be possible to illuminate it. I demurred each time, until my parent's most recent move which would have the piece in storage for a couple of years.  This combined with my guess that the technology was sufficiently advanced to make it possible at an economical price finally convinced me to try it.

The piece as seen in my parent's house (left) and back illuminated (right).  To see how the illumination works, click here for a slide show.

I consider this a first approximation of how this could work and the result merely a working protoype. Here's  why.


Design Goals

1. Illuminate the art from behind and sufficiently to be viewed in a lighted room.
2. Maintain the free-floating appearance on the wall.

Solution

From the beginning I thought the unit would have to be able to run on batteries so that an elctrical cord wouldn't spoil the effect of the sculpture floating on the wall.  This meant using LEDs as the light source, but I was unfamiliar with the options available.

The piece is about 13-inches square.  No prefab LED panel was available, and I wasn't going to spring for a custom one just for testing.  I tried a set of edge lighting LEDs from Luminedge.  The LEDs were certainly bright enough, but when I tried to attach them directly to the artworks white acrylic square the white proved too opaque and in any case, probably wouldn't cause enough of the light to diffuse forward and do so uniformly.

Aware that this is exactly the problem solved in LCD monitors, I bought a used one at Goodwill for $15.  I disassembled it and removed the sophisticated optics system for redirecting and diffusing the edge lighting.  I replaced the fluorescent tubes with the LEDs from Luminedge and cut the acrylic panel to slightly smaller than the art.  I didn't use all the sheets of optical paper used in the LCD. for one thing, there is a larger gap (about 3/4") between the art and the illuminated panel, afforded by the stand-offs, to allow the light to diffuse.

The effect was immediately satisfying.

The next challenge was where to put the batteries.  I initially mocked up putting them on the frame's edge, but decided against it due to my negative perception of the appearance it had on the frame.  I now think it is a better approach.

I then concluded that the batteries could go between the stand-offs and thus the custom battery case shown.  It is not as easy as it looks to make one, let alone one that works well.

The problem of getting power to the panel from the pack proved difficult.    For obvious reasons I didn't think a plug-in solution would work.

Once I had the illumination working I tested the run-time on batteries; about 12 hours was possible.  I concluded a timing circuit would be necessary to ensure the illumination would not be left on.  After evaluating a few I settled on a small, one hour timer circuit kit from Vellerman (K2579).
Even this kits diminutive size proved too much to place elegantly without increasing the depth.  Reluctantly I located it on the back, adding perhaps a half inch of depth and even that required relocating the circuit's largest component (the relay) off-board.
Issues With This Design

1. The battery pack requires a lot of handling of the art to change the batteries.
2. The battery pack casts a shadow on the unlighted sides.
3. The switches cast a shadow,
4. The depth is too great due to the timing circuit.
5. The timer always functions (no "always on") and always for one hour.

 Version 2.0 should address these shortcomings, but for now I'm just enjoying this new, illuminating view.