3. Circuit Diagrams

Overview

Students represent their circuits by making drawings, and then conduct a Gallery Walk to evaluate the drawings. The drawings are likely to be hard to interpret. To solve this problem, students learn to use standard circuit symbols and rules for making diagrams, and use these for explaining their circuits, troubleshooting, and designing new circuits.

Advance Preparation

Photocopy worksheet and Assessment (downloadable at bottom of page)
Post the Standard Circuit Symbols, the Rules for making Circuit Diagrams and a sample circuit diagram (click here to see them)

Materials

Circuits made in Lesson 2
Batteries, LEDs, buzzers, materials for making switches
Worksheet: Circuit Diagrams (downloadable at bottom of page)

Procedure

Circuit drawings: Ask students to make a drawing of a circuit they have already made, or a new one they make quickly. The drawing should be detailed enough so that someone else could construct the same circuit using the drawing as a guide. See a video showing a typical drawing.
Gallery walk: Post all the students’ circuit drawings on a wall or board, and ask students to look at them carefully. Conduct a discussion about what they have noticed. What kinds of problems they ran into in making them? How they are different from one another? What problems would someone else have in understanding them?
Symbols: It is likely that students will have represented the same items differently in their drawings. These differences could make it difficult for people to understand one another’s drawings. Introduce the idea that standard symbols can help us with this problem, if everyone agrees on what the symbols mean. See a video showing examples of standard symbols.
Standard circuit symbols: Introduce the standard circuit symbols for wire, battery, LED, buzzer, switch and motor (click here for additional information). Distribute the worksheet and ask students to complete Part 1.
Designing with circuit diagrams: Diagrams are not only useful for understanding circuits, but also for designing new ones. Click here for examples of how to design new circuits using diagrams.