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Purpose
Purpose
In this unit, participants will learn the skills necessary to create e-textiles (circuits made with conductive thread). Participants will begin with an icebreaker activity to get to know one another and build commonality. They will be introduced to different circuit types such as simple, series, and parallel circuits, and basic hand sewing skills such as threading a needle, basic stitch types, and tying a knot. At the end of the lesson, participants will reflect on what had been learned (circuitry and abstraction).
Materials
Materials
For each participant:
🙿 Felt
🙿 Printouts of People Bingo Template
🙿 Needles
🙿 Regular Thread
🙿 Conductive Thread
🙿 Scissors
🙿 Scrap fabric
🙿 3 volt coin battery
🙿 9 volt battery
🙿 9 volt battery connector
🙿 LED
🙿 Alligator leads
🙿 Pliers
🙿 LED lights
🙿 Hot glue gun
🙿 writing utensils (markers, pencils, pens)
General:
🙿 Multimeter
🙿 Whiteboard
🙿 Example expressive electronic
Vocabulary
Vocabulary
Circuit
Battery
Current
Voltage
LED
Conductive material
Insulating material
Resistor
Parallel circuit
Series circuit
Phase 1: Ice Breaker (15 minutes)
Phase 1: Ice Breaker (15 minutes)
People Bingo
- Handout people bingo cards to participants
- Explain to participants that the first person to fill 5 boxes across or down wins a prize! Incentive prizes can be full-sized candy bars, packaged desserts, maybe water-color kits, journals, pens, slime, etc…
- Participants will fill boxes by finding other participants that fit the traits listed on the bingo squares. They must put the person's name in the corresponding box or have the person sign the appropriate square.
- Ask participants not to ask more than 2 questions per person.
- Give participants 10 to 15 minutes to complete the activity
Phase 2: Introduction to Circuits (60 - 75 minutes)
Phase 2: Introduction to Circuits (60 - 75 minutes)
EXPLAIN MAJOR CIRCUIT PARTS
If we were to decompose a circuit into individual parts, it would include:
Battery
Circuits start with a power source. The power source for us today is a coin battery.
Current
The amount of electrons flowing in a circuit during a period of time. The rate of the flow is measured in amperes, known as Amps.
Voltage
You can’t have current without an energy source pushing the electrons. Voltage is the amount of potential energy (or electrical pressure) in a source like a battery. Voltage is like water pressure: the higher the voltage, the more it can push electrons through a circuit.
LED
A Light Emitting Diode (LED) is a diode that emits light when a current flows through it. An LED has two terminals (or legs). The longer end is the positive end (+) and the shorter end is the negative end (-).
Conductive material
A conductive material is any material that allows electricity to flow from one point of the circuit to another point. Common conductive materials are wires made out of copper and copper tape. For example, when you want to light a lamp, you need a wire or a conductive material to run the current from the power source, usually a wall outlet, to the light bulb.
Circuit
All of these smaller component parts can be put together to create a circuit. A circuit is a path that charged particles take as they move from one side of a power source to another.
Q: Can you think of an example of where you might see a circuit in your house?
CIRCUIT DIAGRAM PUZZLE
1. Print our the Circuit Diagram Puzzle in Appendix (double sided)
2. Ask the participants to cut the basic circuit parts and put them to represent a simple circuit using the definition/vocabularies printed on the back of each part.
3. Demonstrate an example and wrap up.
CREATE SIMPLE CIRCUIT
1. Pass out the following: [1] 9-volt battery, [1] 9-volt battery connector, [1] 3-volt battery, [6] alligator clips, [1] 300-330 ohm resistor, [6] LEDs.
2. Have participants examine the materials. Make sure they recognize the following:
- “+” symbol on the battery identifies the (cathode), which is the side of the battery with a positive charge
- “-” or the other unmarked side of the battery identifies the (anode), which is the side of the battery with a negative charge
- Amount of voltage on each of the batteries
- One LED leg is longer than the other. The longer end is the positive end (+) and the shorter end is the negative end (-).
3. Ask the participants to gather [1] LED and [1] 3V coin cell battery.
4. Ask the participants to touch the positive terminal of the LED to the positive end of the battery and the negative terminal of the LED to the negative side of the battery. The LED should light up! The participants have created their first simple circuit.
5. Invite the participants to explain how the simple circuit is working based on what they’ve learned.
INTRODUCE RESISTANCE
Resistance
A resistor is an electrical component that limits or regulates the flow of electrons (current) in a circuit.
Each resistor has colored stripes to let you know how many electrons per second can flow through a circuit
Create Simple Circuit with Alligator Clips
1. Demonstrate how to create a simple circuit using alligator clips, a 3V battery, and an LED. An alligator clip is a spring loaded metal clip attached to a wire that is used for making temporary electrical connections.
2. Have the students create their own simple circuit using the alligator clips.
Blow a Circuit!
Note to Facilitator: Make sure you have fresh batteries or batteries that you have tested on the multimeter for this activity.
1. Demonstrate blowing out a circuit with the 9 volt battery, two alligator clips, and the LED.
2. Ask students beforehand to watch the LED closely. It will light up for a moment and then burn out.
3. Invite the students to provide explanations for why the LED blew out.
4. Explain that the LED blew out because there was too much voltage flowing to it, therefore damaging the light.
Most LEDs require a forward voltage between 1.8 and 3.3 volts to properly light up. The amount of voltage required to properly light the LED varies by the color of the LED.
Resources:
Reference video- how to check a battery using a multimeter
Add a Resistor
1. Demonstrate the same circuit with a new LED and adding the 300-330 ohm resistor to the circuit.
2. Invite students to provide explanations for why the LED did NOT blow out this time.
3. Explain that the LED did not blow because resistance was added, causing only an amount of volagate the LED could handle to be delivered to the light.
Since most LEDs require a forward voltage between 1.8 and 3.3 volts, a safe rule of thumb for avoiding blowing out the LED light is to not use a power source (battery) that exceeds the voltage required.
Optional: You can also use Ohm's law to figure out what value of resistor you will need. This cheat sheet provides the typical forward voltage and current for different colors of LEDs.
Or handy calculator to figure out which resistor you will need for a simple circuit and parallel and series circuits
Phase 3: Introduction to Series and Parallel Circuits (60-75 minutes)
Phase 3: Introduction to Series and Parallel Circuits (60-75 minutes)
CREATING A SERIES CIRCUIT WITH A 3 VOLT BATTERY
1. Explain that series circuits provide one path for the current to flow like a simple circuit but a key difference is that you can add multiple LEDs in a chain.
2. Explain that when chaining LEDs in a series, you need to make sure that the positive leg of an LED connects to the negative leg of the next LED.
3. Have participants complete a series circuit using alligator clips, 3 LEDs, and a 3V coin cell battery.
[Note: You are asking the students to use 3 LEDS because it will demonstrate that a 3V battery does not have adequate voltage to light 3 LEDs in a series.]
4. The LEDs should either not light up or light up very dimly. Ask participants to hypothesize why this is happening.
[Answer: Each LED has a forward voltage that is required to activate the light. The more LEDs you add to a series circuit, the more voltage that is required to efficiently and effectively light an LED]
CREATING A SERIES CIRCUIT WITH A 9 VOLT
1. Ask participants to swap out the coin cell battery for a 9v battery.
[Note: You are asking the students to use 3 LEDS because it will demonstrate that a 3V battery does not have adequate voltage to light 3 LEDs in a series.]
2. Ask participants to hypothesize why a 9V battery worked better.
[Answer: The LEDs are brighter because we increased the voltage from 3v to 9v]
3. Explain that as a general rule, in a series circuit, when you are trying to figure out how much voltage is required to light the LEDs, you need to add the forward voltage of each LED. In this example, we need a 9V battery because we have 3 LEDs that each require 3V (3V+3V+3V=9V).
Remember that different LEDs have different forward voltages. Refer to the LED cheat sheet provided below in “Appendix”
EXPLAINING A PARALLEL CIRCUIT
1. Ask participants what similarities they see between the series and parallel circuits.
[Answer: Making a parallel circuit is very similar to the other circuits we have built. If we use abstraction to identify the main elements across different circuit types, we see that simple, series, and parallel circuits have components that are common to all circuits: a power source, conductive material, and LED(s).]
2. Parallel circuits are useful because if one LED is broken, it will only create a gap that impacts that particular path. The LEDs in the other paths will still work because those paths will remain closed.
CREATING A PARALLEL CIRCUIT
1. Have participants complete a parallel circuit using alligator clips, 3v battery, and 3 LEDs.
2. Ask participants why they think the 3v worked on 3 LED’s in this circuit, but not the series circuit?
EXPLORE CIRCUITS
Give participants free time to experiment with the materials and create their own simple, series, and parallel circuits with the materials in their toolkits. You can even encourage them to work with other people and combine materials to create a long chain of LEDs.
Phase 4: Introduction to Basic Sewing Skills (15-20 minutes)
Phase 4: Introduction to Basic Sewing Skills (15-20 minutes)
You can demonstrate it together with the Hand-Sewing Basic video and ask the participants to practice step-by-step.
SECURING A KNOT
1. Wrap the threads around your finger, roll it between your thumb and index finger, then pull to make it a knot.
RUNNING STITCH
2. Use when stitching something quickly or to obtain a “gathered” appearance by pulling the threads.
TYING OFF
3. Make 2-3 tying-off stitches
BACK-STITCH
4. Use when you need a stronger stitch. First, make a normal stitch, then start the second stitch from where the first one ended.
BLANKET STITCH
5. Use when stitching two edges together. For the first stitch insert the needle in the same place, pass the needle through the loop and pull. Then insert the needle a small distance from the first stitch. Pass the needle through the loop and pull.
Phase 5: Make a Shiny Star Pin (30 minutes)
Phase 5: Make a Shiny Star Pin (30 minutes)
Let's practice making shiny star pin.
- Cut a piece of felt in the shape of a star
- Arrange the LEDs and the battery holder on a piece of felt according to the template
- Mark the positive leg of the LED with Sharpies. Use pliers to curl the legs of the LED lights so that they can be sewn to the felt.
- Sew the circuit onto the felt according to the dot lines on the template.
- Cut a long conductive thread and sew the positive end of the battery holder with the positive leg of the LED together.
- Cut another long conductive thread and sew the negative end of the battery with the negative leg of the LED together.
5. Attach the pin to the felt with hot glue
Star Template.pdfPhase 6: Reflection (15-20 minutes)
Phase 6: Reflection (15-20 minutes)
Decomposition
1. Review Decomposition: Breaking a problem down into smaller, manageable parts.
2. Ask participants to describe how they used decomposition to learn about circuits.
[Answer: They broke down the circuit into parts - conductive path, LED, battery - in order to understand how it works]
Abstraction
1. Review Abstraction: Removing specifics to find commonalities.
2. Ask participants to describe how they used abstraction to learn about circuits.
[Answer: Although they learned three different circuit types (simple, series, and parallel), they were able to understand that despite specifics like different numbers of LEDs or battery voltages, all circuits still had the same main components - a battery that provides current and voltage, a conductive path like alligator leads, and an LED]
Reflection
1. Ask each participant to reflect on what they learned today and share it with the group.
[Note: The facilitator can ask one participant to share what she learned. Once the participant answers the question, the participant can then ask another participant to share what she learned and so on until all participants have spoken]
2. Did anyone have any problems making their circuits work? How did you overcome it?
3. How did you help someone today?
4. What did it feel like when you got a circuit to work?
5. If you were to explain the parts of a circuit and how it works, what would you say?
6. Would you say you understand the parts of a circuit and how a circuit works better than when we started today? Why or why not?
Appendix
Appendix
Circuit Diagram Puzzle
Circuit Diagram Puzzle.pdfLED Voltage Sheet
LED Voltages.pdfStar Template
Star Template.pdfReport abuse