Ultra-thin USB powered light box


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Just a word of warning: these have either no or poor over-voltage protection. Store them unplugged.

We bought a few to have around lab (I’m a physicist that studies squishy stuff). A student left one plugged in over a 1 week vacation and the battery swelled up and split the case. Luckily we noticed and unplugged the thing before something more exciting happened.

That said, we immediately bought more. They aren’t nearly as bright as more expensive light boxes, but are impressively uniform, and having 3mm-thick, cordless lighting gives us incredible versatility. They’re great!

From what I understand, they were originally marketed towards quilters?


Oh wow, if I still did physical work on a regular basis that would be pretty sweet.

These days I find that my very occasional lightbox needs can be fulfilled by filling my tablet’s screen with white and setting the brightness to maximum. I’ve even used this as a way to enlarge a sketch: photograph it, zoom in, and put paper on top of it.


I wrote to Wacom to suggest that they add something like this to their Bamboo graphics tablets, although it might be nice on other ones too. My “avatar” if it shows up, was made by scanning and tracing a photo of myself and then coloring it… and it would have been easier if I could have done the tracing right on the tablet.


If you want a build-your-own version, pick up the howto here:

I made myself one from a broken laptop display, obtained for free from a laptop service shop. (I got a stack of them.) The backlights are pretty good for this purpose. The rest was replacing the LCD panel with a cut-to-size piece of 2mm glass, and making a chain of SMD LEDs with appropriate resistors, fed from 12 volts. (A 5V version for USB or phone charger power could be doable too. That one could be also powered from a power bank, for portability.)


The big ol’ iPad Pro should be a pretty nice, if not exactly cost-effective lightbox.


You can make one from a cracked or otherwise decommissioned large monitor or flatscreen TV. With a bit of luck the backlight may still be working, eliminating the need of replacing it. Some of the power supply boards even have descriptions of the connector pins on the silkscreen so without major reverse engineering you can attach a switch for powering it on, and optionally a PWM circuit for regulating brightness.

(If you have to do the reversing, most of the pins are outputs, connected directly to those big-ass caps in the PSU outputs (these caps die often and are the primary cause of such screens’ decommissioning, so you can easily score a free monitor), and the higher-current ones can be several connected in parallel. That look-and-see will eliminate most of the pins. Then you get one that goes to the high voltage part of the PSU, where the backlight power is generated for the CCFLs, one that enables the high power part of the PSU (there’s a low-power that provides standby 5V), and maybe one or two others. You’ll need to connect the latter in a way that enables the PSU, and then attach the backlight control one(s) in a way to light up the CCFLs.)


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