While this version of the card requires the recipient to own or purchase two crocodile clip connectors, I created a simple battery holder in later versions by crossing the two strips of conductive tape and sandwiching the 3V button battery in between.
Please see illustration for optimal solution (though it does not correspond exactly with the photos I took of my first example) >> Download illustration
I reproduced this Christmas card 20 times, mailed them out from Austria and hope that they all arrived.
Step 1: Materials and Tools
- Conductive thread from http://www.sparkfun.com or http://www.lessemf.com
also see http://cnmat.berkeley.edu/resource/conductive_thread
- Conductive tape from http://wwwl.essemf.com
- 3V button battery (and holder)
- Crocodile clips
- Regular colored thread
- Nice colored cardboard
- Decorative pens
- Scissors or cutting knife and mat
- Sewing machine
Step 2: Cutting, Drawing and Sticking
Cut two small tabs of conductive tape (aprox. 1 x 1 cm) and tape them to the bottom left on the back side (not like in the photos, where I taped it to the front side where the conductive stitch is not).
Step 3: Sewing
Starting from the bottom conductive tab stitch back and forth and then across to the Christmas tree trunk and then up to the top and end the stitch by doubling back on yourself at least once.
Start the stitch again about 0,5 1 cm to the left of where you just ended it. Sew to the left back towards the upper conductive tab and in between create another gap by ending and re-starting the conductive stitch.
Now you can clip off all the loose threads, EXCEPT those of the switch. Here you can clip the non-conductive regular thread but not the loose conductive threads. These must be brought to the front side of the card and tied to a bow. To close the switch and complete the flow of electricity though the LED.
Step 4: Set-up
Insert the legs of the LED into the stitch holes at the top of the Christmas tree. Make sure that the legs are making contact with the conductive thread and bend them if necessary (see photos).
Clip the crocodile clips to the conductive tabs and connect them to the right side of the battery, depending on how you inserted your LED (just try which way round works).
To turn off the light undo the bow, remove the LED or unclip a crocodile clip.