In honor of all my good friends still over in Japan I've decided to create an Instructable for a $3 Emergency Solar Radio. It's a great thing in case of tsunami, nuclear melt down, or zombie invasion. Plus it's really cute when put into an Altoids tin.

My plan is to send this as a (slightly) joke birthday gift to a good friend of mine living in California, who just so happens to be freaking out about possible nuclear clouds. This will also be really nice for her when she starts going camping again this summer.

The design is very simple and only takes about 45 minutes to put together, less if you know what you're doing.

If you'd rather not make one yourself, I'll probably be throwing up a couple completed ones as well as most of the parts over at my website BrownDogGadgets.com.

Step 1: What You Need

I bought all the supplies I needed from my local $1 Store. (If in Japan, a 100 Yen store.)

To buy:
1x FM Radio
2x Solar Garden Light
1x Diode ($1 for 100 of them online, or take one out of any random junk pile)

If your local $1 Store isn't as cool as mine, you can probably find these things locally, online (like at my website BrownDogGadgets.com), or from a trash bin.

Soldering Iron
Wire Strippers

Altoids Tin
Hot Glue
Mini Speakers ($1 Store, or take apart old headphones)

Support Me By Buying Some Parts...

If you can't find solar cells or cheap AAA batteries, I have quite a few on my website BrownDogGadgets.com. The same solar cells I use to make my Solar Cockroach would work great for this project. You could also slap on a bigger, more powerful cell onto the outside of the tin like these nice 4.5 volt cells.

I also some AAA battery holders and very cheap AAA batteries for sale that have a much higher capacity than the ones you'd find in your average solar light.

<p>This is amazing! I want to use the same idea, but with LED lights. What type of safety precautions would I need to do this?</p><p>Thanks!</p>
I made one too, but as a case I took a Cigarette Box and glued all the electric parts inside. Also I figured out which circuit is delivering power when I turn on this radio and I soldered an indicator Led to the circuit. It's a pretty nice Radio and has a really good sound. This will take its place in my Camping and BOB bag
<p>What wire did you use</p><p>What kind of FM radio is that (i cant really find one of those online)</p><p>What tape did you use</p>
<p>If it's powered by the Sun do you need the batteries?</p>
yes, if you want to use it at night, or in a heavy storm, or inside
<p>As jerry.ericsson2 pointed out AM is what ya need. FM is line of sight. I can key up the Limark repeater system from the top of bear Mountain along the Hudson River on 1 watt from an HT on a crappy rubber duck, but at sea level you gotta be close. If the stinky brown stuff hits the whirley bird thing AM is what what will hear important info, not FM. </p><p>A really nice am Xtal radio with a plug in wire antenna might be useful If you can couple it to a small amp, then it can be heard by all, w/o cans, (headphones).</p><p>There used to be am radio receiver modules you could buy or you can gut a small am radio. They usually are crap, but if you make an external antenna option or a &quot;kludge&quot;,( kludge has many meanings), but I refer to a table top antenna that is a cross on a base with a coil spun around it like a web. One could glue a giant coil of say 22 guage enameled wire on a flap of stiffish canvas and you have a rollable coil antenna. So when you hoist your food supply up into a tree to keep the bears from eating it first, your antenna is up high. Course you can just as easily tie the end of the wire to the bag you hoist up as well. </p><p>That said I liked you toy it has merit as a starting point. Unfortunately Lindsay's publications is out of business......he had all the books you could imagine on this stuff. The simple horn speaker attachments you see for smart phones can be used to amplify a Xtal earpiece so you do not need a set of phone. I think multiple parallel antenna strands would also help. </p><p>here is a book I saved from the recycle truck:</p><p><a href="https://archive.org/details/principlesunderl00unitrich">https://archive.org/details/principlesunderl00unit...</a></p><p>If you got through HS Physics and want to understand how radio works try it from page one to the end. I took radio repair in in HS and I got it, but this is more basic, it predates superheterodyne receivers. Spark Gap Transmitters/receivers. </p>
<p>Cool indeed. I would put one of these together, but here on the great plains of South Dakota, FM radio is only a dream that is realized when we travel to bigger cites where such signals exist. In fact here in the small town on the prairie where I exist, even Ham radio operators such as myself need a very tall antenna to reach any other Ham's even on common talk around bands, such as the 2 meter. The only option would be an AM radio, and as such would not be very useful in an Altoids Can.</p>
why do you have to drill on step 7????? <br>
<p>I have dozens of old drills laying around but when it comes to these cans, I never use them. I simply use screwdrivers to punch the holes. I start with a small driver and work my way up to the size I need. The tin is so thin that it is easy and much quicker then drilling.</p>
<p>To make a hole for an earphone jack</p>
<p>Oh,my radio is the same as yours.</p>
<p>Man I gotta say, this type of project must do wonders for Altoids sales! I never tried an Altoids until I got into project building. Now you can find me sucking on these wonderful little mints day and night, just to get those cans empty so I can do another project. My most recent was an Arduino based oscilloscope that fits the can nicely with a small 84X48 monochrome screen, using a 9V rechargable battery as power supply.</p>
<p>Super well done!</p>
<p>Rage quit</p>
<p>I used the same radio, but the wires connecting to the battery came off the plastic case as I was removing the housing, and now I can't get them back on. How are these little wires affixed originally when the radio comes from the store, with glue? Or am I just better off buying another little radio to start again?</p>
<p>This is a beautifully elegant little radio. You have done very well to make it for so little money, I am very impressed!</p>
<p>Where did you get that one type of radio? I looked everywhere, and the only place I found it was Alibaba, but it was only in 5000 piece bulk package. I am in North Carolina, if there are any specific stores that have it here.</p>
<p>Hey nice instructable, i have a few questions though.</p><p>First, can i use a solar cell from a calculator?</p><p>Second, does it have to be a specific diode?</p><p>Third, can i use normal batteries instead of those used for solar cells?</p><p>Fourth, whats the diode for?</p>
<p>1) No, not strong enough by a mile.</p><p>2) 1N914 is the standard and super common one to use.</p><p>3) No, you need rechargeables so they can recharge. Regular batteries will... possibly leak or explode.</p>
<p> I could (almost) make one of these following these instructions. I even have everything I need already. I was going to say except for the diode, but odds are there are some floating around here somewhere...</p><p>Just one question: Why do you have to throw the solar cell away if you break off the solder point? Can't you just re-solder it? I know this was already asked, but I don't see an answer, and I was wondering the same thing. </p>
<p>With these type of cells if you break off the solder point, then there is no way to make a connection. If you use better solar cells you'll have an easier time. I was just using super cheap recycled $1 Store solar cells. Spending $5 on a better solar cell will make life a lot better.</p>
<p>Ah... I see. Thank you for your reply. I know nothing about these kinds of things and it just seemed like it was wasteful to throw it away. </p>
<p>Would a Digitally Tuned radio work??</p><p>(see this one I found - http://www.dollargeneral.com/product/index.jsp?pro...</p>
<p>Probably. </p>
<p>i made it!!!!!! hahaa. its easy enough</p>
<p>Just FYI, the reason that this works and receives a signal through the Altoids tin is because the headphones are the antenna. If you use speakers, you might need a separate FM antenna. Hope this helps.</p>
<p>If you break off the solder point from the solar cell, couldn't you just solder it back on?</p>
<p>you misspelt goggles</p>
found 2 separate lights around the house. one has a 2/3 aa battery and its panel puts out 1.2v and the other has a AA battery and its panel puts out .95-.97 volts sitting under 40w bulb(it was night out). which panel do i use and how many. also do i need the diode?
Quick tip:<br>When buying solar powered lights for this, look for blue solar panels.<br>They are usually higher quality than the dark brown ones.
thanks good to know
Very true. Those CIS are dark brown and very high quality...
This has got to be one of the single most coolest things on instructables!
what kind of tap do I use o step 8???
I just began making this when I realized I'm out of diodes. Will it still function without one?
Cool project! I think I have all that I need to make this laying around so I'll definitely do it.
What diode do I use?
i suggest a schematic diagram for the project. please to make things simple
Whatat does the diode do in the circuit? Just curious
awesome idea and well written, i can buy cheap radio with a scan button and a return one
Just because I'm a teacher doesn't mean that I'm not human.<br><br>With feelings to be hurt...<br><br>Sniff...
teachers are awesome c:
Altoid tins are neat, but maybe an easier more practical project would be to just add the charging panels directly to the radio case? Or, maybe the panels glued to a plastic pocket-shaped sheet and connected by a sturdy wire to the radio battery compartment. Then you would have a solar charging case for the radio.
Probably, but this is rather bare bones. Plus cute. You gotta factor in the cute aspect.
What type of diode did you use?
&nbsp;The current carrying capability, the voltage rating and the voltage drop across the diode are considerations. Too much current can harm the diode, too much over voltage drop, the batteries may not fully charge. Nominal figures; for the silicon diode used here is .7 V, for the Schottky diode it's .2 V. In most solar application the Schottky is preferred, but one can't walk into radio shack and buy one. In low powered projects like this, it's easier to add an extra salvage solar cell, and used the more readily available silicone diode. No precision is required on the voltage rating here as long as it's higher than the battery voltage, the voltage rating is important if the diode will see a reverse bias as part as normal desired operation.
1N914. Very common. You can find them everywhere.

About This Instructable




Bio: I used to teach middle school science, but now I run my own online educational science website. I spend my days designing new projects for ... More »
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