LED Quilt Circuits

Let's light up our quilt squares using the included LEDs (which stands for "Light-Emitting Diode") by making an electrical circuit with them.  Here are some things to note about electrical circuits and LEDs:

• For this project, you can imagine that a circuit is a bit like a small, circular chain of electronic parts:  The chain "links" are made out of the conductive thread, with the start of the chain linking one side (or "pole") of a power supply (a AA battery, for example, is a type of power supply), then linking up to each LED in a row, and then finally linking back to the other side of the battery.

• A circuit set up in this "chain-like" way, with only one path coming and going to each LED, is called a "series" circuit!

• You might wonder, "isn't there a way to have multiple paths in a circuit?".  Yes, and that is called a "parallel" circuit.  However, you will find that combining LEDs of different colors in using a parallel circuit may result in some of those LEDs not lighting up! You will have the most luck lighting all of them by hooking them up in series.  The order of the colors is all up to you, though!

• LEDs are picky about the way they are wired up: they have a "positive" side (also called the "anode") and "negative" side (or the "cathode").  So it can be said that LEDs have a particular "polarity".  The reason is because LEDs only allow current to flow (and so will only light up) if the positive side of the LED is connected toward the positive side of the power supply, and the negative side of the LED toward the negative side of the power supply.  If your LED is not lighting up, it might be wired in backward! Try connecting it the other way around to see if that fixes it.

• Extending the idea above: for LEDs wired in series, if any one LED in the circuit is wired in backward, it will block the flow of current in the circuit — which also means any other LEDs on the chain (even if wired with the correct polarity) will not light, either! You will have to make sure all LEDs are connected with the correct polarity in your circuit.

• Feel free to be creative in terms of the layout of your quilt section; but one rule to follow is to have the positive "tail" (that is, where the power supply would connect) of your circuit placed at the the top edge of your quilt piece, and the negative tail placed at the bottom edge.  This will make running power to each piece easy when they are all combined into the final quilt.