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LED Light Box Answered

Normally, a light box uses fluorescent lamps (e.g. 36 watts Philips Lamp) and electronic ballasts to emit light. However, it consumes too much electricty and the life of lamps is short. Therefore, I would like to replace fluorescent lamps with LEDs.


Of course you can use it. Now LEDs and the technology for driving such LEDs is available. So a big Yes. You can do it and it will be easy to control the light output also.

Just measure the light output and try to have LEDs that provide somewhat more output than needed. Get the right driver for them and voila, you are in business !

Have you looked at cold cathode tubes? Cheap, low power consumption, long life, VERY cool (temperature wise as well as aesthetically) and are reasonably easy to diffuse if you need to, meaning their "hot spots" are not really spots but more like the fluorescent tubes. Any number of common translucent materials diffuse the light very well - just try different things to get the right affect for the particular application. You can also use a reflective material (even aluminum foil sometimes) on the frame piece beneath the lights to help gett more efficiency while providing some diffusion also. Google "computer case mods" or "computer case lighting" to get lots of places that sell them. They usually come with inverters that plug into "molex" connectors on a computer motherboard for power, but a 12v, 1A wall wart can be easily adapted to provide the necessary power. You probably have several wall warts that meet that description lying around from old phone chargers or any number of other common things. I figure on less than $10 per pair (almost always sold in pairs) including power and a nice looking on/off switch. They typically come in 12" lengths and there's a decent selection of colors available including UV.

You will need a lot of LEDs but there are ways to reduce bright spots. You could mount your LEDs around the edge near the front facing the back onto white paper or a frosted reflector. Or you could make an edge lit plastic sheet (see https://www.instructables.com/id/Edge-Lit-Displays/) with LEDs all around the edge and a very slight sand blast, no pattern, and a mirror (or sheet of aluminum foil) behind it. Either of these would go behind the typical frosted glass front. The second one would be thin enough to carry around and lay on top of any handy desk or table.

The reason that fluorscent lamps are used is because they produce the most light with the smallest amount of heat. Also, the light emitted by the lamp is spread out evenly along its length, thus making the diffusion of the light under the viewing object more even. That's not to say that an LED version couldn't be produced, but the diffusion of the light would certainly have to be addressed. The LED version would have "hot" spots unless one used MANY LEDs. If one tried to produce more diffusion more opacity in the top surface, then that would also reduce the light output.