Picture of 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.

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:
Sewing machine
Embroidery Needle and Thread
Soldering iron
Heat gun or matches
Wire cutters
Sith lightsaber

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.
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BrunoG4 years ago
Stop stealing joules!!!!!!!!!!!!!
Domo Kun is asking why you didn't use him instead?
harringtron7 years ago
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...
unknownuser2007 (author)  harringtron7 years ago
Thanks for the vote! : -)

I bought it from a place called Less EMF.

Oh, I forgot another shout out.
Leah Buechley's site has much about textile electronics
Great info!

Yeah the fridge reminds me of the old Road Runner cartoons when the Coyote splats against a wall. : - )
the road runner cartoons were funny.
jarjar7616 years ago
hey just for a tip u could put a video on this if u can itll realy help us on how it works
maintman7126 years ago
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&B
unknownuser2007 (author)  maintman7126 years ago
Great! : )
brunoip6 years ago
nice work
unknownuser2007 (author)  brunoip6 years ago
Thank you! : )
amando966 years ago
aww it's cute lol maybe get like a chair or something for him to sit on while he eats?
unknownuser2007 (author)  amando966 years ago
Hey that's a good idea! : )
I continued upon your great idea and made some cute cyborg zombies feeding on “dead” batteries.
unknownuser2007 (author)  masynmachien6 years ago
Great job! : - )
eygen6 years ago
That's awesome! A cat is really suitable for this :P Also, great instructable!
unknownuser2007 (author)  eygen6 years ago
Thank you! : )
botronics7 years ago
You can add a CDS photo resistor from the transistor base to emitter and make it shut down during the day. At night, when you need the light, it will come on. I made mine into an artbot for Robogames 08. I used two series white LEDs. Current draw is about 20 to 30 ma when on at night and 1 ma when its daylight and off.
unknownuser2007 (author)  botronics7 years ago
Thanks for the suggestion! I was wondering how I could add this to the circuit but I'm better at building than I am at designing. Do you recommend a particular value of CDS photo resistor? Or better yet, do you have a Digikey or Mouser part number? : - ) BTW-Great artbot!
Electronic goldmine has a nice assortment of CDS for 3 bucks.Good deal!
Just about any CDS photo resistor will work. i can look up a number for you and post it later. You can change the sensitivity by changing the value of the 1k base resistor. The larger the value, the darker it needs to be for the led to come on. Try something like 10k to 33k. If you put a 50k to 100k pot in series with the 1K, you can make it adjustable.
unknownuser2007 (author)  botronics7 years ago
Thank you very much for the response! I appreciate your help! I'll try it out on my next Joule Thief project!
botronics7 years ago
My joule thief is now blinking! The battery voltage is about .6 volts. I see the voltage drops a bit when it blinks, then it will come back up and blink again. The rate started at 1 per second and has slowed down now. I started a chart of the voltage with a data logging system at work and will run it over the weekend (its still been blinking for days) till it dies. I have a movie of the blinking effect at my youtube site. The led is a resistor type, NOT a blinking led. has anyone seen this effect?
i found 15 toroid's in my old x-box!!!! as well as 2 Leds with super long leads and a bunch of transistors, and resisters (most of the leads are way to short i could solder longer ones but im lazy).
Great! I have enough parts to make four Joule Thiefs! Future Instructables. :-)
btw great instructable.
clamoring7 years ago
unknownuser2007 (author)  clamoring7 years ago
Thank you! : - )
WattSekunde7 years ago
Really great use of the Joule Thief! You can increase the efficiency factor dramatically by adding a small 4.7 nF (1 ... 10 nF) Capacitor parallel to the Resistor. Try with different values.
unknownuser2007 (author)  WattSekunde7 years ago
Thank you. I'll try that! : - )
jonrb7 years ago
Love it!!! Cute and functional!!!
unknownuser2007 (author)  jonrb7 years ago
Thank you! : - )
sleepydog7 years ago
What a wonderful, professionally done Instructable!!!
If you added a cadmium sulfide cell you could make the thief wait until dark to light up (two LEDs would make creepy glowing eyes). Here's a circuit that could be adapted: http://www.instructables.com/id/SD5RPK4F23Z347A/
I can't help wondering what other powered circuitry you could stuff inside this little guy, digital thermometer, cheap FM radio, cell phone charger (via a cord in the tail of course)...
unknownuser2007 (author)  sleepydog7 years ago
Thanks for the idea and the link. I happen to have the same thought this morning! :- )
u can just use a magnet to drain a battery's power.
unknownuser2007 (author)  Chuah Lu Sheng7 years ago
Really? Wow. : - )
Tobi42427 years ago
Very creative.
unknownuser2007 (author)  Tobi42427 years ago
Thank you! : -)
guyfrom7up7 years ago
congrats on getting on make
unknownuser2007 (author)  guyfrom7up7 years ago
Thanks! Yeah, that's a first for me. Flicker already had a user named "unknownuser2007" so I had to create "garagemonkeysan". : - )
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