At a glance
Pairs · four class periods of work time — Unit 4, Days 8, 9, 12 and 13 — then demonstrated on Day 14 · Format: a built prototype, a design log, and a plan of action
The device is built by the two of you and it is shared. Your design log is yours alone, kept in your own words, and so is your page on where the power comes from. I mark each of you on your own log and your own diagram, against the rows below — those two documents are the whole of your mark, and there is no common group mark on this task. The demonstration is how the class sees what you built; it is not separately marked.
The task
Design, build, and test a working device that solves a real problem using an electric circuit. Constraints: battery power only, under $15 in materials, must fit in a shoebox.
The engineering design process
graph LR A["Define the problem"] --> B["Research"] B --> C["Brainstorm"] C --> D["Choose and plan"] D --> E["Build"] E --> F["Test"] F --> G["Improve"] G -->|"as many times as needed"| E
The loop is not decoration. I expect at least two trips around it, and your log must show what failed the first time.
Past examples that worked well
- A moisture sensor that lights up when a plant needs water
- A door alarm using a reed switch
- A hand-crank generator charging a capacitor
- A continuity tester for finding breaks in cables
Your design log
Keep it as you go, not afterwards. It carries most of the marks.
| Section | What goes in it |
|---|---|
| Problem | Who has it, and how you know |
| Research | What exists already; what you borrowed |
| Design | Circuit diagram with component values |
| Build | What actually happened, including mistakes |
| Test | Data, not impressions |
| Improve | What you changed and what it did |
A working device with no log scores lower than a failed device with a good one
The curriculum expectation is about the process. A prototype that failed for reasons you understood and documented demonstrates more than one that worked by luck.
Where the power comes from
Your device runs on a battery. One page, alongside the build:
- The energy behind it. Trace the electricity in this building back to how it was generated, and name one benefit and one cost of that method — social, environmental, or economic.
- Who is affected. Generation and consumption land differently on different communities. Name one community affected by the method that powers this school, and say how.
- A plan of action. One realistic change — in this room, this building, or your home — that would reduce electrical energy use or shift when it is used. Say what it would save, what it would cost, and whose decision it is. A plan nobody could act on is a wish.
Success criteria
| Quality | What it looks like in your work |
|---|---|
| A problem that is really somebody’s | The person who has it is named, and how you found out is in the log |
| A circuit you can account for | Drawn to convention with component values, and every part in it doing a job you can name out loud |
| Two trips around the loop, visible | The first version, what failed, what you changed, and what the change did — one change at a time |
| Tests that produce numbers | Measurements with units, taken the same way each time, instead of “it worked better” |
| The energy behind it, followed | Where the electricity in this building comes from, one benefit, one cost, and a community affected |
| A plan somebody could act on | One realistic change, what it saves, what it costs, and whose decision it is |
Run these over your own log at the start of the last working period — Judging Your Own Work is the routine — and spend the rest of that period on the row you called weakest.
Hand in
- The device
- Design log, one per person
- Circuit diagram drawn to convention — see Circuit Diagram Practice
- Two minutes demonstrating it to the class
Curriculum connection
A1.3
apply an engineering design process and associated skills to design, build, and test devices, models, structures, and/or systems
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A2.1
design an experiment or a prototype to explore a problem relevant to a STEM-related occupation, such as a skilled trade, using findings from research
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D2.3
identify the components of a direct current (DC) circuit and explain their functions, and identify electrical quantities, their symbols, and their corresponding International System of Units (SI) units
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D1.1
assess social, environmental, and economic benefits and challenges resulting from the production of electrical energy from various sources
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D1.2
evaluate how electrical energy production and consumption impact various communities locally or globally, and describe ways to achieve sustainable practices
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D1.3
develop a plan of action to address a local or global electrical energy production or consumption issue, including strategies for energy conservation
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