Project: System Diagnostics
An Electrical Engineering Consultation
Designed for Lead Engineer Martin & Assistant Investigator
This lesson utilizes low-demand, highly collaborative language to support Pathological Demand Avoidance (PDA). Instead of direct instructions, we use "I wonder" statements, invitations, and options. Martin is addressed as an equal colleague. No childish simplified terms are used; we treat the physics with real engineering vocabulary.
Required Materials
- One Device: A smartphone, tablet, or computer with internet access.
- Software (Free/No Install): PhET Circuit Construction Kit: DC - Virtual Lab (This professional simulation tool runs directly in any mobile or desktop browser).
Collaborative Objectives
- Explore the continuous loop required for electric current.
- Investigate what causes a short circuit versus a functional circuit.
- Design and test a digital schematic to power a light source.
Success Benchmarks
- A virtual bulb successfully illuminates.
- Identify how to stop current flow safely.
- Explain the flow of electrons using the system model.
Phase 1The Briefing: System Mechanics
To begin, open the PhET Simulator on the device and lay it between you and Martin. Do not give direct instructions to touch it yet. Start by posing a real engineering puzzle.
"I was looking at this system simulator and got stuck. It simulates actual electrical engineering labs. I’m trying to figure out how electrons—these microscopic packets of energy—actually make the leap from a battery into a bulb. Apparently, if the loop has even a microscopic gap, everything freezes. I wonder if this screen actually behaves like real-world physics?"
The Concept: Explain that electricity isn't magic; it is the physical movement of electrons. They only move if they have a complete, unbroken highway (a closed circuit) leading from the power source (negative terminal) back to the power source (positive terminal).
Phase 2Active Diagnostics & Sandbox Simulation
In this phase, hand control of the device over to Martin. Avoid telling him what to click. Instead, use invitations of choice to guide the learning.
Step 1: Component Analysis (I Do / We Do)
Drag a battery and a lightbulb onto the screen to demonstrate. Do not connect them yet.
- "We have wires, batteries, and bulbs on the left. Which component should we drag out first to test?"
- "I'm curious if we can make a light turn on using only one wire, or if we absolutely need two."
Step 2: Establishing a Closed Loop (We Do / You Do)
Allow Martin to connect the virtual wires to the battery and bulb. If the bulb doesn't light, work together as diagnostic partners.
- "Huh, it's not lighting up yet. I wonder if the electrons are getting stuck at the metal casing of the bulb or if they need to touch a different part?"
- "Let's see if the simulator shows the paths of the blue dots (electrons). Are they moving or stationary right now?"
Step 3: The Danger Zone - Short Circuits (You Do)
Encourage an experiment that real engineers try to avoid: a short circuit. Connect a wire directly from one end of the battery to the other without going through the bulb.
- "I heard there is a way to make the battery catch fire in this simulator by creating a 'short circuit.' I think it happens when electrons have an path with zero resistance. Should we see if we can trigger that safety warning?"
- "Look at how fast those blue dots are moving now! Why do you think they ignored the lightbulb entirely when we gave them that shortcut wire?"
Phase 3Debrief & Consultant Report
To close the session, ask Martin to summarize his findings as the Lead Consultant. Avoid testing him directly ("What is a circuit?"). Instead, ask him to explain how you could fix a real-world problem based on what he just saw.
Real-World Case Study Discussion
"Imagine we have a flashlight that suddenly stopped working. Based on your virtual diagnostics today, what are the top two places on that flashlight we should check for a system failure?"
For electricity to perform work (like making light or turning a motor), it must travel in a complete, unbroken circle. A switch simply acts as a drawbridge—opening the road to stop the electrons, and closing the road to let them work.
Adaptation Protocols
| If Martin Wants to Go Deeper (Extension) | If Engagement Wavers (Scaffolding) |
|---|---|
| Invite him to drag a switch, a resistor, or a fuse into the circuit. Challenge him to create a system where a fuse blows if the current gets too high. | Switch to "Schematic View" (the button with symbols instead of pictures). Ask if he can decipher the secret engineering symbols for battery and bulb, making it feel like cracking a code. |