Cat Burglar Joule Thief

39,984

178

111

Posted

Introduction: Cat Burglar Joule Thief

Make a cat burglar that "steals" left over joules from used batteries. When the cat burglar gets his little paws on a battery his LED nose lights up until all the joules are gone. When drained, recycle the battery. You'll sleep more soundly knowing your batteries are completely dead.

It takes a thief to make a thief. I "stole" two Weekend Projects from Makezine and combined them into one. The Sympathy Doll and the famous Joule Thief. (BTW-Is anyone else having Weekend Project withdrawal symptoms since Bre moved to Etsy? I'm having bedwetting symptoms.)

What's a Joule Thief? A Joule Thief is a simple circuit that uses the last amount of energy (a joule) in a used battery. In essence, it's a battery drainer. It's a great little project by itself.

I'd like to give a "shout out" to others that have I've stolen from, er I mean, have inspired me.
http://blog.makezine.com/archive/2008/01/led_softie.html
http://www.emanator.demon.co.uk/bigclive/joule.htm

This is a pretty easy Instructable. If you ignore family and food, you can do this in one day. "Sorry, Daddy can't help you with that broken arm; he's trying to MAKE something. Go ask Mommy to set it for you."

You can put this project together with basic tools:
Scissors
Sewing machine
Embroidery Needle and Thread
Soldering iron
Heat gun or matches
Wire cutters
Sith lightsaber

Parts:
Solid Core Ferrite Suppressors - Mouser - PN 875-28B0500-100 - $0.18
26 awg wire - Frys - $2.99/roll
Transistor - Mouser - PN 610-2N3904 - $0.10
White LED 10,000 mcd - Frys - $3.49
Resistor 1/4 watt - Frys - $0.95 4 Pack
Conductive Fabric "Zelt" - Less EMF http://www.lessemf.com/fabric.html
Pieces of gray and pink felt - Michaels - $0.20/sheet
Black fleece - JoAnne Fabric - $4.99/yd.
Googlee eyes - Michaels - $0.89/Pack
2 small strong magnets
Shrink tubing
Foam rubber or other stuffing
Fabric glue
Silicone glue
Box of Cap'n Crunch

I swear I put this project together before the "Get the LED Out Contest." It just happens to be great timing because I need to win that t-shirt. I'm actually writing this topless and it's really cold where I'm at. So please leave me a good rating.

Step 1: Design a Sympathy Doll

First you need to design your doll. This is where you can get creative. Design something cute or bizarre. Go crazy!

Pencil out a pattern on paper. I designed a cat burglar because they like to steal jewels.
Get it? Jewels/joules (same pronunciation)? No? Forget it.

Whatever you design, make sure it's large enough to fit all the electrical components. The photo shows the pattern with all the electronic guts laid out. Your design should also be wide enough so that the paws and arms will wrap around a biggie D size battery.

The silver "paws" are conductive fabric called "Zelt." Zelt is great stuff. I use Zelt for many of my projects. Zelt feels good against the skin. I use Zelt as a toga when I go to Tesla coil parties.

Step 2: Make the Paws

From the pattern you just made, estimate the paw size and cut it out of the conductive fabric, Zelt. Then solder some pieces of wire on each. The wires should be long enough to be able to solder them up outside of the cat body (see Step 5). Reinforce this connection with a dab of silicone glue.

Next, take each of the magnets and glue them on to each of the paws. Use strong magnets but keep them apart from one another during the gluing process. You can see in the photos I got mine too close and made a mess of things.

The only magnets that I could find in my chest of trinket treasures (box of junk) were broken but they still worked fine. Also make sure the magnets are positioned so that the opposite poles are facing one another. Why? Because when your cat burglar is finished, the paws will "clasp" together. Awww cute.

At this point you may be asking yourself: "What did I just make here?" I asked the same thing after I had my third kid. Basically, what you just made are the positive and negative contacts for the battery. The magnet backing is used to stick the contacts (paws) to the metal leads of the battery. A simple solution, instead of using some kind of spring contraption.

Step 3: Sew Like a Banshee

Next, cut out your pattern and pin it to a layer of fabric. Trace the pattern onto the fabric. You can use a sewing pencil or chalk. Remove the pattern.

Cut out holes for the paws. Then from the backside, sew the conductive paws you made in the previous step.

Flip the fabric to the front and create the face. First cut a very small hole for the LED nose. Using felt, create the gray mask and pink nose. The pink nose should cover the small hole you just made for the nose. Use fabric glue or sew the pieces to the fabric. Add a little smirking mouth with needle and pink thread.

Now drag out the sewing machine. Cut a small strip of gray felt to create the back of the mask.
Align it, add some fabric glue. Then place the backside fabric over everything making a kind of "fabric sandwich". Pin it all up; then you're ready to sew it up on the machine. Simply follow the pencil/chalk tracing. Do not sew the entire perimeter; leave a few inches so that you can eventually turn everything inside out. We'll call this opening the "stuffing seam."

If you're as good as me with needle and thread, you'll need to clean out your puncture wounds with Bactine before moving on to the next step.

Visit the Makezine site for more (i.e. better) information.

Step 4: MAKE the Joule Thief

Now that you've cleaned your puncture wounds you should be ready to burn yourself.

Drag out the soldering iron, wire cutters, shrink tubing, matches and the other electrical components.

First thing you need to do is the most important. Pay attention! Open up another Window on your browser and go here to find out how to make a Joule Thief.
Makezine does such a great job at explaining things. In truth, I'm just a fat, lazy slob who's tired of one finger typing.

Not funny? Well the next step is...

Step 5: Stuff It!

Okay, don't be an idiot like me. Here's a "something-I'd-do-differently-if-I-was-stupid-enough-to-make-this-again" hint. Before sewing together the "fabric sandwich", you'll want to glue the LED nose in first. Duh! I failed to do this which made final assembly and stuffing it very difficult.

Saying it differently and in English - assemble your Joule Thief with all the components except the conductive paws and the LED. The paws and nose should already be attached to the fabric before turning it inside out.

Turn the doll ("fabric sandwich") inside out. You can access the wires for the paws and LED through the "stuffing seam." Solder and heat shrink these wires into the Joule Thief circuit.

Insert the Joule Thief circuit into the doll and stuff it with bits of shredded foam rubber. Instead of foam rubber you can use other non conductive stuffing material like: sock lint, hairballs or gray matter.

When you're stuffing it, make sure you don't short or break any of the wires like I did. No, I lied; I didn't break or short anything. I'm just a peon at work so I get a power rush when I nag on others.

Step 6: Finish It!

After sewing up the "stuffing seam" with hidden stitching, you're ready to add the details.

From scraps of black fabric sew up a tail. Just take two layers of fabric and sew up a kind of crooked tube. Cut the "tube" out and turn it inside out. Sew the tail to the body. This is important! I provided a photo to show the tail goes on the BACK.

Adding small details really help. Add whiskers with black thread. With pink thread, stitch in a "+" symbol on the positive paw. Glue on some googlee eyes. Lastly, cut small out small triangles from the pink felt and glued them to the ears.

You're done! Now go find some used batteries to drain!

I know you're probably wondering, "What can I do with my Cat Burglar Joule Thief after all my batteries are drained?" You can use it as a fridge magnet or a backpack buddy! Dudes, these are chick magnets! Take one of these to your local biker bar and hotties will be lining up! (Warning: I cannot be held responsible for any pummeling or destruction of property.)

Thanks for looking! :-)

Share

    Recommendations

    • Science of Cooking

      Science of Cooking
    • Microcontroller Contest

      Microcontroller Contest
    • Spotless Contest

      Spotless Contest
    user

    We have a be nice policy.
    Please be positive and constructive.

    Tips

    Questions

    112 Comments

    Stop stealing joules!!!!!!!!!!!!!

    Domo Kun is asking why you didn't use him instead?

    OMG OMG THIS IS SUCH A GOOD IDEA!!!!!! ALSO WHAT ABOUT PUTTING IN A BRIGHT LIGHT SO YOU CAN USE THIS AS A READING LIGHT FOR LAZY/SICK DAYS!!!!!

    This is great! It's useful and the steps are pretty clearly demonstrated. You've got my vote so far. I want to make one and send you my version but I don't know where to obtain Zelt. Good luck! I like that it sits on the fridge waiting, waiting...

    the road runner cartoons were funny.

    hey just for a tip u could put a video on this if u can itll realy help us on how it works

    Hey, there, Greetings from Florida..... Tried the joule thief, just to see if and how it'll work... talk about a surprise...I'm gonna consult with my wife, who is more crafty than I am. Thanks for the idea. K