$3 Emergency Solar Radio

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.

Tools:
Soldering Iron
Drill
Wire
Wire Strippers
Googles
Tape

Optional:
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.

Comments

[Doctor-X17]

I like this project. Both versions look good, but you might be able to use speakers as you planned for the first version if you included an audio amplifier circuit. I'm not sure how small one could be made, though, or if it's feasible in terms of power consumption, but it might be a challenge for you to step up to! But internal speakers or not, this is a good Instructable. Keep up the good work :D

Also, anything in preparation for the Zombie Apocalypse is good.

[dasimpson1981]

you just need to make a altoids hand crank for the time you may not have sun lol or wind turbine in a altoids tin pmsl

[sanyo8088]

cool portable fm radio

[nafaa]

waw , that's cool.

[green_emi]

Great little device... can't wait see what you'll put in an Altoid case next!
Haven't see any similar kind of case here in Ireland but I'll be on the lookout.
Thanks!

[DAND]

What type of diode did you use?

[JoshuaZimmerman]

1N914. Very common. You can find them everywhere.

[earm99]

Thanks for the great instructables!
quick question
Are there any differences if you use a 1n914, a 1n4005 or a 1n5819?

[JoshuaZimmerman]

1N914 us just really really common and has a low voltage drop. It's very handy for low voltage low current systems like in this one.

Google the other diodes and check the voltage drop. They probably would work fine for this kind of setup.

[JoshuaZimmerman]

Just because I'm a teacher doesn't mean that I'm not human.

With feelings to be hurt...

Sniff...

[tgray1]

You're a teacher, so I know you misspelled "knob" just to see if your students are paying attention... right?

[srayner371]

I am just getting into this and am becoming addicted. I have ordered some kits off your website but was wondering for one thing what is the best gauge of wire to buy first to use for these projects?

[JoshuaZimmerman]

I like 22 gage stranded. That seems to be a good size to work with.

[Kirbsome!]

Quick tip:
When buying solar powered lights for this, look for blue solar panels.
They are usually higher quality than the dark brown ones.

[JoshuaZimmerman]

Very true. Those CIS are dark brown and very high quality...

[icej75]

When drilling thin material i have found that by placing a peice of wood behind it, you get a good "base" for drilling and reduce the drill flare on the inside.

[JoshuaZimmerman]

Me too! Thats a great tip.

[SinAmos]

Why is this funny? Because I just took apart some solar lights that stopped charging those 600 mah batteries. I checked the ability of them to produce power with my power meter, which they were still able to do, but at a lesser rate. Then, the two solar lamps you have in your instructable actually have turned up at the 99 cent store for a buck a piece. Going back to what someone else mentioned, the option to turn off the lamps while still letting them charge the batteries is possible. That way, they just charge the batteries, which you remove and put into your battery. Combining them is probably more cumbersome.

[JoshuaZimmerman]

Its very easy to set up a simple circuit using a transistor and a resistor to make your LEDs turn off in sunlight. Most solar lights use that same system internally. Most solar lights use one AA or AAA battery and a solar cell greater than 3.5 volts. The most common reason they fail is because the battery wears out. Replacing the battery is, usually, extreamly easy. I've done that for my parents several times. Don't throw out that light, just replace the battery. If you need batteries I have heaps of cheap ones that I buy for my website. They're the same ones I used to replace the batteries in my parent's solar light. Give my website a try and get some batteries. BrownDogGadgets.com

[macrumpton]

This is a cool project, but rather than pulling apart the radio to make a radio, I wonder if it would not make more sense to just make a solar battery charger so you could use the charged batteries in anything that needs them.

[JoshuaZimmerman]

You could. Or you could just solder the solar panels onto the oiginal FM Radio body, but where would the fun be in that?

The goal was to have an Emergency Radio in a compact case. Something to throw into your "Emergency" bag, First Aid kit, or to take camping.

Also it's just a bit more fun to build it all into an Altoids tin. If you're cafeful you can build in headphones so that the entire project is self contained. I was able to fit in headphone during my second try, but I used smaller and more efficient solar panels. That jumped the price up to about $6 for the entire thing.

Really for between $3-6 it's not a bad project, and is much cheaper than buying a off the shelf emergency radio.