Cute Tilt Beam Flashlight Adds Some Fun Interaction to Your Patio Table

Tilt-Beam-assembly

Here’s a cute little LED hack for your next soiree, it’s a solar charged piece of wood… with a motion controlled light in it!

[Zach DeBord] decided to try building his own version of this after seeing a commercial offering. He took a piece of oak and sliced off the top edge, and then laser cut the exact profile of the solar panel out of that slice. This allowed him to drill a nice big sloppy hole in the middle of it to fit the circuitry.

He’s using a nice big 8mm LED with a small 0.09V-5V DC boost circuit, a mercury tilt switch, a 4.5V solar cell, and a 2.7V 10MF super capacitor — plus a diode and 100ohm resistor. He’s glued the top slice of wood back in place, and sealed the entire thing with resin — you can hardly see the cut mark!

Leave the light with the solar panel facing up during the day, and when evening comes around, simply flip it on its edge to light up your table. And since it’s a super-capacitor, the circuit will likely last longer than you do. We’re not too sure how long the light lasts after a charge though.

Or if you really want to impress your guests, why not make a solar powered remote controlled lawn mower?

Comments

  1. I have heard about huge 100F capacitors , but 10MF , dman…

  2. Tony says:

    I wonder why he used a 5v module rather than ~3v one (other than “I had one on the shelf”).

    • TacticalNinja says:

      It’s because you don’t always have that much sunlight, much less indoors, since this is an indoor gadget. Also, if you notice the diode in-series with the capacitor, it would lower the voltage, so the capacitor would be receiving like 3.5 volts or something on normal lighting conditions.

      • nslenders says:

        which is still more than the cap is rated for. especially super caps don’t like this

        • Tony says:

          I was thinking more the resistor on the LED (why waste power?) but I did notice the 5v solar panel hooked directly to the supercap (2.5v).

          Since the boost module will (probably) work from ~1-3v, a 2.5v solar panel (same area, twice the current) would have been a better match.

          Might be ok if the solar panel current is low, but it’ll be a bit of a bugger to pull it apart and fix it. Reminds me of this: http://kevtris.org/Projects/led/flasher.html, I wonder if it still works some 15 years later.

          • Greenaum says:

            The actual power you get from solar panels, vs rated, is often about a quarter, for anywhere other than a desert on a particularly sunny day. And drawing max possible current will bring the voltage down a bit. Still, tho, would’ve been better to use a lower-voltage panel. Or 2 capacitors in series, even with the consequent loss in capacitance, the extra voltage would partly make up for it. Supercaps are pretty tightly rated for voltage, then again the full 5V would only be present when it’s full. With the small panel the voltage stored in it might never get that high.

            Thinking about it, it’s a fairly complex thing to analyse, real-world. Everything’s so variable, in practice.

          • Tony says:

            Dunno about small cells, but I did notice that 12v ones (say 300x300mm) would give over 20v (open circuit), but still over 12v with a load in full sun.

            I’m not sure how much of a load a 2.5v supercap would be.

            More interesting was comparing some old panels with allegedly super-duper superior new ones; the new ones were resin encapsulated but were highly directional, unless pointed more-or-less directly at the sun they produced little power. The older ones generated power at any angle, and so outperformed the others overall.

            I’ve never checked to see if those little panels are like that too, maybe that’s why those garden lights are crap (besides the battery).

            The supercap might only be subject to high voltage for short periods. Time will tell, I suppose.

            Everything is indeed variable.

          • Greenaum says:

            Like you say, it depends on the load. Certainly with a reasonable load on some solar cells of mine, they gave a quarter of the rated current if you were lucky, under ordinary daylight. Directly pointed at a bright sun in summer, for the brightest couple hours of the day, in between clouds, and they could give something nearer nominal.

            Voltage varied too, but not as much as the current did. Taking too much current caused the voltage to pretty much drop to zero. I had it all metered up specially.

        • TacticalNinja says:

          I may have over estimated (or not), but my Symet is still alive though ;-)

        • nslenders says:

          a 2.7V zener in series with a resistor over the supercap would at least protect the cap. 20c of components to protect a $5 component seems a good solution

          • Bogdan says:

            Except that the diode leakage might be more than what the solar cell gives. Probably a 3V zenner, lowest power will be better.

    • Zach DeBord says:

      The panels are over-volted because they never receive full sunlight. I was trying to make the resin as white and opaque as possible to not show the solar panels, but still charge in reasonable sunlight.

      • Greenaum says:

        Still, supercaps really really don’t have much slack in them voltage-wise, certainly not the amount you’re exposing them to.

        I’d be happier chancing it if I’d measured the voltage from the cell, and also across the cap. Both while in-circuit, and include testing under bright light.

      • Greenaum says:

        Oh, also… just realised what you said about covering the solar panel with resin. It’s the current that’d suffer more from lack of light, rather than voltage. Secondly if you think about the colour white… and light… You’re kindof on to a loser trying to paint a solar panel! Any cover at all is losing power. You may as well just use a smaller panel. Or just accept it’s necessary for a solar panel to be visible in the visible frequencies! A nice design should make it non-ugly. The crystals in a solar cell can be quite attractive to the eye.

  3. Bogdan says:

    I like the idea, but maybe, just maybe, that converter is 0.9V input, not 0.09V?
    A part list would be nice from the project builder…

  4. fartface says:

    Note the laser cutting is just being tech lazy. Sitting down with a chisel you can do the exact same thing with a $15.00 tool, if you you must have “more power” use a small router. I’m all for using technology, but learn the old crafts as well, it probably took as much time to saw off the slice, and set up the laser to do the cutting than it does to simply use a nice small wood chisel and do the same thing. But laser cutting a nice hardwood does smell wonderful.

  5. NoPinky says:

    10MF 2.7V cap seems to be bugging only 1 or 2 people. So… Are there really 10MF 2.7V caps of that size available at this moment?? I doubt that

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