Simple solar charged light box

Thread Starter


Joined Feb 10, 2014
Hi, this is a little something i'd like to make for a very late valentines present ; ) I have a printer and cutting machine and some conductive ink, and want to create a small card box with silhouettes and low powered led light inside that can change colour.

It's to use in the uk, behind we have any electrical solutions to harness the power of sarcasm? that would be handy, but all i can suggest is something like a 9-12cm square solar panel to sit on top which would charge a battery (ideas?), and allow for an uber low-powered change-colour led.

If possible, i'd like to use conductive ink ( to 'draw' I/O switches to toggle when touched by a fingertip; one for I/O, and one to toggle between colours.

Does that sound plausible? i'm a total newbie and don't really know where to start (my background is design) but i'd like it to last, and i'd like to know that the specced solar panel and battery would absorb more than enough in grey conditions to power a teeny light for at least a couple of hours use. Any ideas on the setup i'd require?



Joined Aug 7, 2008
For the sarcasim powered box, I'd use 3 bright bi-coloerd LED's, for battery, just 0ne. Solar panel 12 cm sq. might give 8 V OC & 100 mA,SC, enough to charge 3 Ni-Cd AA cells in direct sun. Might use a C 555 as touch control one shot?? See Bill's Index for throbing LED's. { white box, upper right, this page ]


Joined Sep 9, 2010
I know you could use a comparator (LM339 for instance) to sense a touch. I speculate that you might also use a 555 to both sense the touch and to debounce the switching. (Look up monostable multivibrator or "one shot" circuits using 555.)

Once you have the switch, you could use a counter such as 4017 to give you the various output states that change each time you hit the switch. One touch for blue, next for red, etc. That sort of thing.

I'd be tempted to get one of those solar lights that changes colors, and hack it to add a bigger PV panel to it. It seems like it is close to what you want already and it would solve some of your issues. Time is running out. ;)