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Description

This 1 hour electricity challenge is ideal for participants of all ages. Using a hands-on game, youth will explore future thinking, systems thinking, and user-centred design; improve their collaboration and teamwork, creativity, and problem solving skills, and garner confidence, entrepreneurship, and leadership.

Lesson

Big Ideas

  1. In current electricity, electrons move through a circuit (a loop). A circuit must be complete in order for electrons to flow. If a circuit is not complete, no electricity flows.
  2. The flow of electrons is called electric current. Electrons move from areas of negative charge to areas of positive charge. (INSTRUCTORS NOTE: conventional current is defined as the flow from positive to negative, and this is how current is show in most circuit diagrams, despite the fact that what is actually occurring is the movement of electrons from negative to positive.)
  3. Circuits can be set up in series or in parallel. How a circuit is set up will affect how things attached to that circuit behave.
  4. Circuits can include things like a power source, switches, output devices, resistors, and capacitors.

What happens when we turn on a light switch, or press the “on” button on a TV? Why are the lights or TV off until we press those buttons? It all has to do with circuits, and with tiny particles called electrons.

Lights, tv sets, radios, hair dryers, computers, and so much more all run on current electricity. Electricity is power, specifically the energy that comes from the movement of tiny particles called electrons. Electrons are incredibly small, and have a negative charge (like the negative end of a battery). As long as electrons are moving, we have electricity (electrical current).

When we turn on a light switch, electrons are able to flow. The energy of that electric current is captured by the light bulb and converted to light energy instead. Turn the switch off, and suddenly electrons are no longer able to flow. No moving electrons, no electricity, and so no light. But how does a switch control whether or not electrons can flow?

Switches control electrical circuits. A circuit is simply a loop that electrons can travel around. If the circuit is not complete (if the loop is broken) then electrons get stuck at the point where the circle breaks (at the switch), and won’t be able to move until the loop is completed again.

A good analogy to explain current, switches, and even resistance, is water pipes and taps. The speed of the water flowing through the tap is like electric current. The tap being opened and closed to either allow or prevent water from flowing is like switches. Finally, the diameter of the pipes can simulate resistance of a circuit; if the pipe is small it will restrict water flow much more than a pipe with a larger diameter.

littleBits are a fun scientific tool that show allow youth to test out how circuits work. Each piece is either an output or an input, the outputs perform functions while the inputs control how much electricity from the battery pack makes its way to the downstream bits. This activity connects with the Codemakers Coded Choreography activity in that it allows campers to control the inputs to dictate what function they would like the output to perform.

The following is a list of the littleBits that are included in this activity and their function:

Power Source - Provides power to all downstream bits
Wire - Extends the space between two bits
Dimmer - Reduces the power supplied to any downstream bit
Light Sensor - Reduces or increases the amount of power to all downstream bits depending on the amount of surrounding light
Temperature Sensor - Increases the amount of power to all downstream bits with increased external temperature
Light wire - Long green light output
RGB LED - Red, green, blue light output
Vibration motor - Moving motor output
Number - Number output

 

Opening Hook

During:

  1. Gather campers in a standing circle. Show the group the energy ball and demonstrate how it works. Introduce the idea of a circuit. With another instructor, demonstrate how electrons can flow through two people and still complete the circuit to power the energy ball. Ask how many people do you think are able join hands before the circuit will not work anymore?
  2. Have the group hold hands in the circle, and test the energy ball. Does it still work? It should. Electrons can zip around any size of circuit we like (which is why power lines can stretch such huge distances between the power plant and our homes).
  3. Repeat the circuit, but experiment with having different campers be the “switch”. What if there are two switches? Does it matter if one switch is on, but the other is off? (In this case yes because we are modelling a series circuit).

Optional Extension to show the difference between parallel and series circuits:

  1. Gather the campers in a standing circle, representing the wires in a series circuit. Label one camper as a battery; this can be done using a piece of construction paper, labelled with “battery”, clipped as a necklace with alligator clips. The battery camper holds a container filled with ping pong balls. These represent the electrons that flow through a circuit. Each camper is only allowed to have one ping pong ball at a time!
  2. Have an instructor set a timer for 1 minute. When the instructor starts the timer the campers start passing the ping pong balls around the circuit.
  3. Label another camper as a switch and start the timer again. An instructor can say “open” and “closed” to tell the switch what to do. If the switch is open, the switch camper stops taking electrons, stopping the current. When the instructor says “close”, the switch camper starts passing the ping pong electrons again and the current is restarted.
    1. *Here you should point out to the campers that if the switch is open, it affects the entire circuit and stops the current because it’s a SERIES circuit.
  4. Take a few students out of the circle and rearrange them into a PARALLEL circuit. You can take as few as 3 campers out to be the new ‘wire’. The camper at the joint where the 2 wires splits will alternate passing a ping pong to both ‘wires’. The campers at the other joint both pass their ping pong balls to the camper in the main circle. Start the timer and run this set up for another minute. This will show the electrons flowing along 2 pathways.
  5. Run the activity again but this time adding the “open” and “closed” calls. This will show that if a switch is open on the parallel wire, the electrons can still flow along the other wire.
  6. Time permitting, run this activity with a switch on both ‘wires’ and show what happens when one is open and the other is closed or when both are open in a parallel circuit.

Activity 1: littleBits Challenge

To Do in Advance:

  1. Set up 10 littleBits stations, each station will include a littleBits kit, and a challenge keyring.  
  2. Divide campers into 10 groups, assign them to a littleBits kit. They will work through the challenge cards at their own pace.

During:

  1. Distribute littleBits kits to each group of campers, they will work through challenges 1-8 on their own time. Each of the challenges gets progressively harder and concludes with a design your own style activity.
  2. Ask campers to consider how the order of the bits affects their circuit. For example: if a circuit is composed of a power bit, an LED light, the dimmer, and a motor, will adjusting the dimmer affect the motor only, the light only, or both output devices? Why? Clarify the importance of order to reinforce the direction of the current.

After:

  1. Have campers pitch their littleBit Designs (challenge #8) to the group.

Modifications and Extensions

Modifications:

  1. Have campers work at their own pace.
  2. Go through the littleBits kit and explain the function of each bit prior to beginning the challenge cards. 

Extensions:

  1. Provide each station with only 5 minutes to complete the challenge.
  2. Allow campers to discover the function of each bit on their own.