This instructable is for solar powered Skull with sinister red LED eyes. It measures about 2 1/2" by 1 3/8", including the USB tab. It has one hole through the top of the board, making hanging easy. Wear it as a necklace, earrings, keychain, bond on a pin, or hang it in a window. The possibilities are up to you, and we'd love to see what you do with them.

The schematic and parts list are included. You are welcome to wire up your own, copying is the sincerest form of flattery. We also have the kit available in our Store.

If you have soldered projects before, this will be easy. There are only 19 pieces to solder onto the board, and all are through hole. Depending on your soldering savvy it may take anywhere from 30 to 45 min. Watch it in action here!

Skull kit01.mp4 from Robin Lawson on Vimeo.

So lets begin!

Step 1: Tools

Here's what you need:

A soldering iron
Diagonal cutters

Helping hands and needle nose pliers are optional, but helpful.

<p>Why did you use a dual comparator if the second output (pin 7) is not connected? Doesn't that waste power (~0.6&micro;A) to have the second one? Otherwise there is a DIP8 version of the 6541 that would work.</p>
I mostly use a dual comparator instead of a single because the extra 0.6uA draw doesn't make the pieces visibly dimmer, while only stocking dual comparators reduces the number of parts we stock. It also lets us add more LED's and blinking phases to a comparator design with minimal disruption. <br><br>If the unused comparator still bugs you, it's easy to recruit. Just lift pin 6 of U1 (-inB) into the air and connect it to pin 1, 5 and/or the pin 6 pad with a resistor and/or capacitor. Pin 7 will now oscillate with some pattern which can then be feed into a copy of the circuit formed by C3, D1, and D2.
Thanks for the instructable. This was a wonderful christmas gift for my wife. Works and looks great! I will be ordering some of the other items you have in your store. Simple and easy to put together. I did hot glue a piece of fabric to the back of the skull. Maybe you could include a piece of felt?
Thanks, I'm glad you enjoyed it. The felt or cloth on the back is a really good suggestion. We will add that to our instructables and look into adding it to the kits.
Sorry correction to my last question, I meant replacing C3 not C2 with a 10uF tantalum.
I wouldn't recommend using a Tantalum cap for C3. The polarity of C3 changes with each flash and Tantalum caps tend to explode if reverse charged. Aluminum electrolytic caps are less volatile, so I'd be willing to try a 10-15 volt 10uF aluminum cap as C3. I'd expect an aluminum cap to work for a few months at least. Lastly eyes have a logarithmic response to brightness, so using a 1uF to 4.7uF ceramic cap for C3 only dims the flashes to about 1/3 as bright. (using a smaller C3 would also let you shrink C5 for faster flashing without hurting run time)
Further question about the hard to find capacitors. If I were to replace C1 with a 47uF tantalum I take it the polarity would be same orientation as the supercap, C2. What about replacing C2, also with a 10uF tantalum, how would its polarity go?
I'm Interested in making this project but I cant source the 47uf fixed ceramic capacitor. Where are these available from. Would a tantalum substitution work
Digikey stocks some TDK capacitors in this size.&nbsp; <a href="http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&KeyWords=445-8540-ND" rel="nofollow">445-8540-ND</a> (or at Mouser <a href="http://www.mouser.com/ProductDetail/TDK/FK26X5R0J476M/?qs=%2fha2pyFadujdLXmBeHcTrf%2fmwj3guKoGBj3sQp7c4tbuwljo2qgZzA%3d%3d" rel="nofollow">810-FK26X5R0J476M</a> )&nbsp; A Tantalum cap or two 22uF ceramic caps in parallel would also work fine.&nbsp; The circuit isn't too picky about what is used for C1 as long as it's a much higher value than C3.&nbsp;
Firstly, a very fine &amp; compact project! <br>5***** ! <br>Now: <br>This seems more of a usb powered led project than a solar one. <br>What is the &quot;solar only&quot; circuit?? (No USB port or USB CHARGING of any kind!) <br>Would this &quot;solar only&quot; circuit just &quot;blink&quot; or throw some light also??! <br>Would like to make a &quot;solar only&quot; circuit - using photodiodes/ldrs, leds, and capacitors (hopefully, no resistors since they are a waste!!) <br> <br>reg <br>ketan
For &quot;solar only&quot; just leave off R6 and the usb-connector.<br> <br> With the above mods, the circuit would still just &quot;blink&quot;. To &quot;throw some light&quot; you either have to accept a much shorter run time, or use a much larger solar array and storage system. (and re-design the circuit to use more power)<br> <br> If you want the simplest &quot;solar only&quot; project that glows, see our <a href="https://www.instructables.com/id/3-piece-solar-powered-LED/" rel="nofollow">3 piece solar powered LED</a> instructable.&nbsp; (which will scale up just fine with different parts)&nbsp; For anything fancier, you're going to need to use a few resistors in your solar project as part of a timing circuit (R1, R3, R4, R5) or as current limiters (R6).&nbsp;
I made a 555 timer led bracelet, I wanted to use a super cap but I cant find where to buy them, is there any online shops you would recommend? <br>https://www.facebook.com/photo.php?v=10200163798636986&amp;set=vb.223939090958358&amp;type=2&amp;theater
I usually buy stuff from <a href="http://www.digikey.com" rel="nofollow">www.digikey.com</a> or <a href="http://www.mouser.com" rel="nofollow">www.mouser.com</a>.&nbsp; They ship fast and let you easily search by component electrical parameters.&nbsp;<br> <br> I'd suggest using<a href="http://www.digikey.com/product-detail/en/KR-5R5V105-R/283-2816-ND/1556244" rel="nofollow"> this super-cap</a> or<a href="http://www.digikey.com/product-detail/en/EEC-S5R5H105/P6981-ND/125088" rel="nofollow"> this super-cap </a>for your bracelet.&nbsp; They should run it for 5-10 minutes on a charge.&nbsp; For better run time I'd also suggest switching to a low power 555 timer like the <a href="http://www.digikey.com/product-detail/en/TS555IN/497-2299-5-ND/599646" rel="nofollow">TS555IN</a>.&nbsp; With a TS555IN, high brightness LEDs, and some power optimization you should be able to get your bracelet to run for 1/2 to 1 hour on a 1F super-cap.&nbsp; You could also pick up a <a href="http://www.digikey.com/product-detail/en/USB-B1KSB6/ED2981-ND/2677742" rel="nofollow">usb-b connector</a> as a convenient charge port.&nbsp;
im using the tlc 555 timer, runs on a minimal of 2 volts (might be 4) the timmer is perfect i just use one small battery. Thanks for the links! Ill look into it
i love this! If i had extra cash I would buy your kit. I love the way the componets are laid out, adds detait to the skull. This is a future purchase!

About This Instructable




Bio: We’re life-long tinkerers, siblings, and fourth generation engineers. We’re not quite sure which of us had the idea of putting LED’s on ... More »
More by lumenjewelry:Solar Powered SM Fox Blinky LED Jewelry LED Fox pendant, Solar Powered kit Rocket Kit - Beginner Solar Powered + LED 
Add instructable to: