This lesson begins by revisiting the classic Batteries and Bulbs unit: students try to make a coin battery light up a LED and turn on a buzzer. Once they have addressed these basic challenges, students can explore lighting up two LED’s, or an LED and a buzzer, in parallel and/or series combinations. The Penguin Race toy is available to provide models of current, voltage, source and load.
Electricity Concepts: Lead a brief review of electric circuits. If students have already done “Batteries and Bulbs” you can use this experience as a starting point (see a video). Another way to illustrate electricity is by demonstrating and discussing the Penguin Race Toy (video). Develop the idea that this toy is a model of a circuit.
Different kinds of batteries and bulbs: Distribute LED’s and coin batteries. Ask students to examine them carefully (video) and notice and record differences from batteries and bulbs they have seen before.
Batteries and Loads: Introduce the term load for a LED, buzzer or anything else that runs from battery (video). Then ask students to experiment with more than one LED or an LED and a buzzer, and/or more than one battery (video).
Homework: Switch hunt. Provide the Switch Hunt Worksheet (downloadable below). Ask students to look for switches at home, and use the worksheet o describe where they found them, what they control and what they operate. See Lesson 2 for a typical list.
To learn about how LED’s work together, you can use a Digital Multi meter (see video). For example, the Multi meter will show you why a red or yellow LED will turn a green or blue one off, when they are both connected to the same battery. More information about the Digital Multi meter is available in the Appendix to ElectroCity.