Practical Activity Guide
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🗂️ How it is marked
This page runs alongside your mock assignment booklet. It
gives you the brief, the ten stages in the order you work
through them, a hint for each one, and a link to the right tool. It gives you
hints, never answers — the design is yours to work out.
This is a mock. It is marked exactly like the real practical
activity, but the marks do not count towards your qualification — they show you and your
teacher what to work on first. The hints below are part of that: in the real assessment you
would not have them, or this page.
Before you ask your teacher, work down this list. Most of
the time you will not reach the bottom.
- Read the stage again in this booklet, and re-read the advice pages at the front.
- Look back at your own earlier work. Your block diagram, truth table, simulation printout and layouts answer most questions about what comes next.
- Check the class website. The practical activity guide has the brief, a hint for every one of the ten stages, and a link to the right tool.
- Use the tool. The Block Diagram Builder, the Stripboard Builder and the simulation, construction and testing pages are all on the site.
- Only then ask your teacher — and say what you have already tried. Working independently is worth 6 marks across construction and wiring.
The brief
Pillar drill warning system
The workshop at Berwickshire Engineering has a pillar drill that is in use all day.
Run continuously, the motor overheats — that shortens the life of the motor and is a
fire risk. The supervisor also needs to know if the emergency stop has been hit, or if
the guard has been left open while the machine is live.
One warning unit is to be fitted to the machine. It must warn if the motor is
overheating, or the emergency stop has been pressed, or
the guard has been left open. The workshop is noisy and ear defenders are worn, so the
warning must be seen as well as heard — a buzzer and a warning lamp,
both operating together.
The real sensors are not available in the lab, so each one is
simulated by a switch. Your circuit must behave exactly as it would
with the real sensors fitted.
Your three inputs
Each one is an SPDT (changeover) switch with a 10 kΩ pull-down resistor.
Read this one twice. Input C reads logic 1 when the machine
is safe, not when there is a fault. Think carefully about what that means
for your design.
Process and output
- Three logic gates, built from 74HC integrated circuits on a 5 V supply.
- Every unused input must be tied to a rail via a 10 kΩ resistor,
or the chip gets warm and switches at random. Unused outputs are left unconnected.
- The output drives a buzzer and an LED together. The LED needs a series resistor.
- Fit test points wherever the voltage matters: both supply rails, every switch output
and the output of every gate.
All of this is in your booklet on p.3–4 — read those pages properly,
don't work from this screen alone.
Overview
The ten stages
Stages 1 to 6 design the system and plan the build on paper. Stages 7, 8 and 9
build, wire and test one sub-system at a time — each board is finished and working
before the next one is started. Your assessor checks and signs every stage before
you begin the next.
The ten stages are the order you work in. The
five tasks in the last column are what your assessor records the marks
against — see how the practical activity is
marked. Keep your record of progress up to date at every stage (booklet p.7–8).
Stages 1 – 3
Designing and costing
Read the brief. Decide what each switch means. Draw the system, prove it on screen, then price it.
Stage 1 — Block diagram
4 marks
Task 1a · Booklet p.9–10
You hand in: Block diagram, truth table and logic diagram
- Read the problem description and the advice pages carefully.
- Create system and sub-system block diagrams for the warning system. Show all inputs and outputs, keep the input, process and output sections separated, and join the blocks with arrows.
- Complete a truth table for your system.
- Draw the logic diagram. Label every input, every output and every point in between.
- Update your record of progress.
Stuck? Try this first
For each input, write down what logic 1 means. Then ask: does the warning need to come on when this input is 1, or when it is 0? An input that is the wrong way round has to be turned round inside your system.
How marks get lost here
- Elements listed rather than joined up with arrows.
- The process section left vague.
- Sections not ruled apart.
Stage 2 — Simulation in Yenka
3 marks
Task 2a · Booklet p.11
You hand in: Yenka printout, sections marked on it
- Build your design in Yenka, exactly as you drew it. No shortcuts.
- Test every row of your truth table.
- Tie every unused input on a 74HC chip to a rail.
- Demonstrate the working simulation to your assessor and keep a printout or screenshot.
- Mark the input, process and output sections on the printout.
- Update your record of progress.
Stuck? Try this first
Build it a gate at a time and test after each one. A simulation that was working two gates ago is much easier to fix.
How marks get lost here
- Only the fault states demonstrated, not all eight.
- Printout attached with nothing marked on it.
Stage 3 — Costing 100 prototypes
3 marks
Task 1b · Booklet p.12
You hand in: Costing table for 100 prototypes
- List every component you need for one unit, including the stripboard, the DIL sockets, the wire, the terminal blocks and the case parts.
- Give each one an item ID. Use the same ID on your layout drawings, in your wiring schedule and in your test plan.
- Go back and write your item IDs onto your Stage 2 simulation printout, so the same ID names the part everywhere.
- Work out how many of each part are needed to build 100 prototypes.
- Price each part by the batch it is sold in, not by the single component, and work out how many batches must be ordered.
- Give the total cost of the 100 prototypes.
- Update your record of progress.
Stuck? Try this first
Look the parts up on Rapid or RS. A batch of 100 resistors usually costs less than ten bought singly — that is why the marks are for batch pricing.
How marks get lost here
- Item IDs never written back onto the Stage 2 simulation printout.
- Unit price times quantity, instead of pricing by the batch.
- Batches not rounded up to a whole batch.
- DIL sockets, the stripboard itself or the wire left off the list.
Stages 4 – 6
Planning the build
The boards, the wiring and the testing are all planned on paper before a single track is cut.
Stage 4 — Stripboard schematic diagrams
4 marks
Task 2b · Booklet p.13
You hand in: Three stripboard layout sheets, attached
- Produce a component layout drawing for each of the three stripboards, on the layout paper issued to you.
- Draw each part as it looks on the board, not as a circuit symbol.
- Mark every track cut and every wire link.
- Mark every test point on the layout, before you build anything.
- Label every part with its item ID from Stage 3.
- Attach all three sheets to this booklet.
- Update your record of progress.
Stuck? Try this first
Count the holes you need before you draw anything, and leave a spare row at each end. Mark the track cuts and the test points first, then fit the components round them.
How marks get lost here
- Track cuts missing.
- Test points not planned onto the layout — fit them here, not when you are already soldering.
- Parts drawn but not labelled with their item ID.
- Sheets not attached to the booklet — they cannot be marked.
Stage 5 — Wiring schedule
marked with the wiring in Stages 7–9
Task 3b · Booklet p.13
You hand in: Completed wiring schedule
- Plan the wiring loom that joins the three boards and the supply.
- Number every wire and record it: colour, where it runs from, where it runs to, and the signal it carries.
- Red is used for the positive supply only and black for the 0 V connection only, on the boards as well as in the loom.
- Give every signal its own colour. If all the signal wires are the same colour, that says every one of those points carries the same signal - which is not true.
- Update your record of progress.
Stuck? Try this first
Decide your colours before you cut any wire, and write them into the schedule. Re-doing a loom costs a lesson.
How marks get lost here
- Red or black used for a signal.
- One colour used for every signal — that says every one of those points carries the same signal.
- Wires made but never written into the schedule.
Stage 6 — Test planning
3 marks
Task 4a · Booklet p.14–18
You hand in: Nine test tables, description columns filled in
- Plan all nine tests before you build anything: a pre-power-up checklist and a functionality test for each of the three boards, plus the simulation test and the complete system twice.
- Fill in the test point and description columns of all nine tables now. Leave the results columns empty.
- For every test, say which point you will measure and what you expect to read there.
- Use a logic probe at the gate inputs and outputs and record the logic level. Use the meter for the supply rails and for any voltage or current you are asked for.
- The last table compares your simulation result with your circuit result, point by point, so fill its simulation column in from your Stage 2 printout.
- Date every row as you carry the test out - the dated tables are your record of testing.
- Update your record of progress.
Stuck? Try this first
Write each description as two halves: what you will do, and what you expect to see. If you cannot say what you expect, you do not yet know what the test is for.
How marks get lost here
- Descriptions written after the testing instead of before it.
- Tables left blank until the board is built.
- Every reading written as a voltage — use a logic probe at the gate pins and record the logic level.
- The ninth table's simulation column left empty.
Stages 7 – 9
One board at a time
48 of the 70 marks. Input, then process, then output — each one finished and tested before the next is started.
Stage 7 — Input sub-system: construct, wire and test
Stages 7–9 together: 48 marks
Tasks 3a, 3b and 4b · Booklet p.14–18
You hand in: Input board built, wired and tested
- Build the input board to your Stage 4 layout, using the materials and techniques you have used during the course.
- Fit the test points as you go. Label the board, and label each switch with what it simulates - not just SW1.
- Wire the board into the loom, following your Stage 5 schedule.
- Carry out the pre-power-up checklist and then the functionality test for this board, and record the results.
- Diagnose any faults, carry out any repairs, and record what you changed.
- Work safely at all times: hold the soldering iron correctly, use the stand and the extractor, and wear eye protection.
- Update your record of progress. You may include photographs.
Stuck? Try this first
Test the input board on its own before you wire anything to it. A fault found on one board takes minutes; the same fault found on three takes a lesson.
How marks get lost here
- Switches labelled SW1, SW2, SW3 with no mention of what each one simulates.
- Unused inputs left untied.
- Components fitted diagonally.
- Test points on the loom only, none at the chips.
- Rows left undated — the dated tables are your record of testing.
- The changes column left blank where nil should be written.
Stage 8 — Process sub-system: construct, wire and test
Stages 7–9 together: 48 marks
Tasks 3a, 3b and 4b · Booklet p.14–18
You hand in: Process board built, wired and tested
- Build the process board to your Stage 4 layout. Fit the DIL sockets before the chips go anywhere near the board.
- Tie every unused input to a rail, exactly as on your layout.
- Fit the test points as you go. Label the board and both chips with their part numbers.
- Wire the board into the loom, following your Stage 5 schedule.
- Carry out the pre-power-up checklist and then the functionality test for this board, and record the results.
- Diagnose any faults, carry out any repairs, and record what you changed.
- Work safely at all times.
- Update your record of progress. You may include photographs.
Stuck? Try this first
Fit the sockets, test the board, and only then put the chips in. Check every tied pin against your layout before you power up.
How marks get lost here
- Switches labelled SW1, SW2, SW3 with no mention of what each one simulates.
- Unused inputs left untied.
- Components fitted diagonally.
- Test points on the loom only, none at the chips.
- Rows left undated — the dated tables are your record of testing.
- The changes column left blank where nil should be written.
Stage 9 — Output sub-system: construct, wire and test
Stages 7–9 together: 48 marks
Tasks 3a, 3b and 4b · Booklet p.14–18
You hand in: Output board built and tested, then the whole system
- Build the output board to your Stage 4 layout, watching the polarity of the LED and the buzzer.
- Fit the test points as you go. Label the board and each output device with what it does.
- Wire the board into the loom, following your Stage 5 schedule. The system is now complete.
- Carry out the pre-power-up checklist and then the functionality test for this board, and record the results.
- With all three boards wired together, carry out the complete system pre-power-up checklist and the test against the specification, comparing each result with your simulation.
- Diagnose any faults, carry out any repairs, and record what you changed.
- Work safely at all times.
- Update your record of progress. You may include photographs.
Stuck? Try this first
When all three boards are joined, work through your truth table one row at a time. The row that behaves wrongly tells you which part of the circuit to look at.
How marks get lost here
- Switches labelled SW1, SW2, SW3 with no mention of what each one simulates.
- Unused inputs left untied.
- Components fitted diagonally.
- Test points on the loom only, none at the chips.
- Rows left undated — the dated tables are your record of testing.
- The changes column left blank where nil should be written.
Stage 10
Evaluation
Five marks that cost nothing but the habit of writing things down as you go.
Stage 10 — Evaluation
5 marks
Task 5 · Booklet p.19–20
You hand in: Record of progress and evaluation
- Report on the tests you carried out, the results, and any changes you made because of them.
- Show evidence of your completed solution.
- Evaluate the completed circuit: explain how it meets the specification and suggest how it could be improved.
- Evaluate how well you carried out the analysis, design, construction and testing.
- Check that your record of progress is complete.
Stuck? Try this first
The challenge does not have to be a disaster. A track cut in the wrong place, found and fixed, is a perfectly good challenge to write about.
How marks get lost here
- A challenge named, but nothing said about what was done about it.
- Logbook gaps, or entries that say only what was worked on.
Testing videos
Watch a test being done
Short demonstrations of how each test is carried out — where to put the
probes, what to look for, and how to record it. They show you the
method, not the answers.
Not yet filmed. These links will go live during the
assessment. Until then they land on the offline-materials page — that is expected, not a
broken link.
There is no video for the simulation test or the whole-system pre-power-up
check: both are done exactly as the board-level ones are, so there is nothing new to show.
📚 Everything in one place
Supplier sites are for prices only. You cost the parts for
Stage 3 — you are not ordering anything.
Sources & credits: brief, stage guidance and hints written by R Stewart, 2026. Task structure and marking-descriptor wording adapted from the National 5 Electronics practical activity (C884 75), © Qualifications Scotland (SQA), reproduced for educational use.
