The Power of Food
Students imagine they are stranded on an island and must create the brightest light possible with the meager supplies they have on hand in order to gain the attention of a rescue airplane. In small groups, students create circuits using items in their "survival kits" to create maximum voltage, measured with a multimeter and two LED lights. To complete the activity, students act as engineers by using the given materials to create circuits that produces the highest voltage and light up the most LED lights. They apply their knowledge of how voltage differs in a series circuit and a parallel circuit to design their solutions.
Students create circuits to achieve the brightest light.Copyright 2013 Lisa Arnold, Central Michigan University
Electrical engineers apply their knowledge of electrical circuits to design solutions (such as creating lights) to defined problems (such as alerting a rescue airplane). Engineers must completely understand the difference between series and parallel circuits as well as the behavior of many other components that can be put into circuits, such as resistors, diodes and capacitors. An example of this is a cell phone, for which an electrical engineer must create a tiny circuit on a computer chip. In the chip are many components that manipulate the current in many ways to cause the phone to do certain things when the buttons are pushed. The same is true for a touch screen phone except sensors are used to detect the location you are touching. Electrical engineers also manipulate the voltage coming out of a wall (electrical) outlet so that the correct amount of voltage is released without burning up (or overheating) whatever is plugged into the socket—such as cell phone chargers. This is accomplished with a circuit and electrical components organized inside of the charger. Often, when designing new products, such as in this activity, engineers are limited by the materials available.
After this activity, students should be able to:
- Explain the difference between resistors in parallel and series to maximize voltage.
- Use engineering techniques to select materials to create a circuit that is able to light LEDs.
- Explain what a diode is and that it is one directional.