Ecuffs
Participants will learn about LEDs and circuits while designing and sewing a personalized ecuff.
Supplies
We'll be using:
felt
conductive thread
regular thread
metal snaps to serve as the "on" switch
3V coin batter holder
3V coin battery
3 LEDs
pliers
alligator clips (to test our circuit)
if time allows, accent buttons
CPL staff received training from the Creativity Labs in 2013. Thank you Diane, Sophia, and Verily!
About LEDs
Let's learn about polarity, or anodes and cathodes. Anodes are the positive end of a battery or LED. In the case of the LED, it is marked by having a longer leg. Let's test this out. Take your 3V battery, and note which side is positive. Take one of your 3 LEDs, and fit the leads over the battery so the longer leg is touching the positive side, and the shorter leg is touching the negative side. It should light if your battery contains energy.
This image is from SparkFun.com, click on it for a very informative tutorial on LEDs and other components.
About the Battery Holder
Our battery holder has two ends, one for positive and the other for negative. On the battery holder is very small, fine print. The print indicates that the "back" of the holder is the negative side, and the "front", or the piece closer to you when holding the hollow face, is positive. The easy way to release a battery from the holder is to press the plastic piece holding it in. The battery should pop right out.
About Conductive Thread
Conductive thread has some resistance of its own.
Testing your LEDs, Marking your LEDs
Test with 3V coin battery, locating the positive and negative side of the battery
Bend anodes into small squares and bend cathodes into small loops.
Using the pliers, turn the squares and loops so they are at a right angle to the LED bulb – this will make it easier for sewing the LEDs onto the felt.
(For future reference, it doesn’t matter which is bent into which shape, as long as you are consistent!)
Diagram of the Parallel Array
Starting at the anode, or positive, end of the battery holder, you will notice the conductive thread travels to the anode of LED1, then to LED2, then to LED3. It stops there.
Then, starting at LED1's cathode, or negative, lead, you will notice the conductive thread travels to the cathode of LED2, then LED3, then it continues to the magnetic snap.
You will notice the magnetic snap on the left connects to the battery's cathode and the magnetic snap on the right connects to the cathode of LED3.
The magnetic snaps do not have an anode or cathode, they merely carry the circuit.
Testing the Array
Although we say this array will work, we can demonstrate that it will work before you sew a single stitch! We can do this with the alligator clips provided. Lay out your battery holder with battery, LEDs and snaps as shown in the diagram.
Where a line segment connects each component to the next, use a pair of alligator clips. You can even clip an alligator clip to the head of another alligator clip if you don't have much space, as in an LED lead.
Animated Example of Sewing the Array
Click on the image to open and view the GIF.
Survey
Surveys are here: https://sites.google.com/site/cplmakerlab/surveys
FYI
LEDs: Light Emitting Diodes are efficient lights, and you can find version of them in flashlights, lamps, and now TVs.
Switches: Switches are mechanisms which complete a circuit, allowing power to flow into lights or other devices.
Series and parallel connections: We'll be using a parallel connection today for our ecuffs, but learn more about the differences and applications.