I begin the lesson by showing students a radio, cell phone, iPad, and other pieces of technology that use diodes to control electricity within the device. I tell students that all of these electronic devices use a special piece of technology, called a diode, to control the flow of electricity. I show the students the diode that they will use in the lesson. I tell the students that the diode will only work in certain ways and that their task is to build a working circuit that includes a diode.
I inform the students that their task today is to build a circuit that includes a diode and functions properly. I ask students to build a circuit tester as they did in a previous lesson. I then ask students to connect the diode to the circuit tester.
It is common for about half of the students to get the circuit to function properly on their first try. It is very important to encourage these students to continue testing with the diode. It is a key experience that students see the diode in different configurations so that they build understanding that the diode only allows electricity to flow in one direction.
The other students may struggle to get the bulb to light up in their circuit. I encourage all students to use what they have learned about the engineering design process and about perseverance to continue to think of and test new solutions. A video of a student pair working with their diode can be found here.
To conclude this lesson, I guide students to use their electricity glossary to review what they have learned in this lesson. While there are no new vocabulary words to define, I ask students to review the glossary words that they have already defined and to make a list of words that apply to the construction of their circuit in today's lesson. I ask students to list these words in their journal. I then ask students to share the words that they chose and to explain why these words applied to the construction of the circuit with the diode. My aim is to have students begin to make connections between the concepts we have studied.