VCE Systems Engineering Unit 1 — Electrotechnological systems design · Stage 6
Weeks 1-2 · Systems, inputs and outputs
Describe any device as input, processing and output, and tell an open-loop system from a closed-loop one.
Open this deck on the projector and press F for full-screen. N toggles speaker notes. The accompanying teacher guide is at /curriculum/vce-systems-engineering-unit-1/teacher/lessons/1.
Before this lesson:
Have one dismantled device on the bench — an old remote, a mouse, a kettle thermostat. Physical beats slides here.
Systems, inputs and outputs
What you will be able to do
Describe any device as input, processing and output, and tell an open-loop system from a closed-loop one.
Have one dismantled device on the bench — an old remote, a mouse, a kettle thermostat. Physical beats slides here.
What we're covering
Make the connection
Pick a device in your home you have never thought about. Work out what it senses, what it decides, and what it changes.
Sort ten devices into open-loop and closed-loop. Be ready to argue about the ones that are hard to place.
Draw block diagrams for two of them.
Read the design brief and highlight every word that constrains what you can build.
Set up your record of evidence and make your first entry.
- Open with a system the students already trust and never think about: a fridge, traffic lights, an automatic door, a phone that dims its own screen. Ask what it senses, what it decides, and what it changes.
- Teach Input → Processing → Output on those examples, then extend to feedback: the fridge measures its own temperature and that measurement changes what it does next.
- Draw the distinction that runs through the whole unit: an open-loop system acts without checking the result (a timer), a closed-loop system measures the result and adjusts (a thermostat). Have students sort a list of ten devices into the two categories and defend the hard ones.
- Introduce block diagrams as the way engineers draw this, and have students diagram two systems from the sorted list.
- Issue the design brief and read it together. Do not start solutions — the point is that students carry the brief for the rest of the semester and it gets sharper as they learn what components can do.
- Set up the record of evidence and explain that it is kept as they go.
Quick check
Show your reasoning
I can draw a block diagram for a device I did not build, and say whether it uses feedback and how I know.
Students often call anything automatic 'closed loop'. A timer is not feedback: it never measures whether the thing it wanted actually happened.
Before you pack up
Explain what you learned
Name one device you will never look at the same way again, and say why.
Block diagrams for two devices; the open/closed sort with reasoning on the contested ones.
End of lesson 1
Explain it. Apply it.
Next lesson: How electrotechnology got here, and what it costs.