OPTIONAL CHALLENGE 15 · BASIC ELECTRONICS
A system may share its supply while allowing independent output control. Function depends on connections, not just the parts present.
Send signals and compare paths
Your new skill: A system may share its supply while allowing independent output control. Function depends on connections, not just the parts present.
Revisit the skill you will reuse: Previous main-path missionPrevious main-path missionPrevious main-path mission
Match the names to your parts before you build. New parts appear when you first need them. You can point, say the name or show a grown-up.
A battery supplies energy that can make a light glow or a motor turn. A holder keeps its connections in place.
Look for: Find the + and - marks and the matching holder or snap connector.
Before using it: Use only the supply named in this mission. Never join + straight to -; disconnect before rewiring.
Your turn: With power disconnected, trace the path from + through the parts and back to -.
A wire makes an electrical connection between two points. A clip lead grips a terminal.
Look for: Jumpers have small plug ends; clip leads have metal jaws. Colour helps us track a connection.
Before using it: Colour does not change a wire's job. Check both ends and keep bare metal away from other terminals.
Your turn: Follow one wire from start to finish and name what it joins.
This reusable building board joins some holes with hidden metal strips, so we can connect parts without soldering.
Look for: Find the centre gap, row numbers and power rails. The gap separates the two halves.
Before using it: Five holes in one numbered strip usually join; the strip across the gap does not. Some power rails have a break. Match your board diagram.
Your turn: Point to two holes on the same connected strip, then two that are separated by the gap.
A resistor limits current in a path. Beside our LED it helps protect the light from too much current. Its resistance is measured in ohms.
Look for: Look for a small body with two legs and coloured bands; match its labelled value to the mission.
Before using it: Use the labelled 2.2 kΩ, 2.7 kΩ or 520 kΩ value specified. A resistor can face either way. Never replace LED current limiting with wire.
Your turn: Point to the resistor in the LED path. Explain why replacing it with a plain wire is not our test.
An LED turns electrical energy into light and works in one direction. We use it to show what a circuit is doing.
Look for: An untrimmed ordinary LED often has a longer anode leg and a shorter cathode leg. A flat rim often marks the cathode.
Before using it: Confirm polarity with the part card if legs are trimmed. Use the mission's resistor in series; never connect an LED straight across the battery.
Your turn: With power off, identify the two legs and point to its protective resistor.
A switch opens or closes a path and stays in the position you choose.
Look for: Find its labelled terminals and the ON and OFF positions.
Before using it: Keep an off-board switch outside the breadboard as instructed; use leads to its terminals. Rewire only with power disconnected.
Your turn: Move it to OFF, then trace the place where it stops the circuit path.
A push button changes an electrical connection while you press it. It gives our circuit a short instruction.
Look for: Match the two-leg or four-leg part to the supplied card. It springs back when released.
Before using it: Our instructions specify the working pair of terminals. A four-leg button has internally joined pairs, so do not guess which pair switches.
Your turn: Press and release it without power. Predict which state will make our signal turn on.
Our active buzzer makes a sound when it receives suitable power. Short and long taps let us send a code.
Look for: Look for the sound opening and + mark; match its voltage range to the part card.
Before using it: An active buzzer has its own sound-making circuit. Switching it on and off changes the rhythm, not a musical pitch.
Your turn: Without powering it, point out + and -. Plan a short tap and a long tap.
WHAT YOU'LL USE
Reuse kit parts between projects. Household materials are listed separately. Match every value, variant and rating before connecting power.
BEFORE YOU BUILD
Disconnect power before every change. Never join battery positive directly to negative. Keep the specified LED resistor in place. Keep metal out of mouths and away from mains sockets. Stop and ask an adult if any part becomes warm or smells unusual.
YOUR REWARD
PREDICT BEFORE YOU BEGIN
Predict the result before testing. You can say it, draw it or point. What evidence would change your prediction?
BEFORE YOU BUILD
Adult setup check: Active buzzer suitable at 9V. If this check cannot be confirmed on your actual parts, read and explore the concept only; do not power the build.
YOUR CHALLENGE
NEW POWER-UP
A system may share its supply while allowing independent output control. Function depends on connections, not just the parts present.
Practise first: 2, 3 and 14. Reuse the familiar circuit before changing one feature.
Each coloured strip is one connected group. Different numbered rows stay separate. This explains the board; use the mission’s exact connection reference for component positions. Check rail breaks on your supplied board.
Four correct combinations of light and sound, with no control unintentionally driving the other branch.
A system may share its supply while allowing independent output control. Function depends on connections, not just the parts present.
What changes from One Control Two Signals? Each output now has its own control.
CONNECTION MAP
BUILD PATH
STEP 1 OF 4
Disconnect and rebuild the two branches with separate controls.
A video demonstration will appear here when it is ready. You can follow the written step now.
Disconnect and rebuild the two branches with separate controls.
WHAT'S REALLY HAPPENING?
A system may share its supply while allowing independent output control. Function depends on connections, not just the parts present.
FAIR-TEST CHALLENGE
Change only the feature named in this project; keep the supply, parts and observation conditions the same. Repeat the comparison.
WHEN IT DOESN'T WORK YET
Likely cause: An open path, wrong node, polarity mismatch or a part variant that needs review.
Try this first: Check for a wire joining the two switched output nodes.
Likely cause: The setup needs adult inspection.
Try this first: Disconnect immediately. Do not retry until the fault is identified.
CLEAN, RESET AND STORE
Switch off and disconnect all power. Let moving parts stop. For capacitor projects, discharge through the 2.2 kΩ resistor for ten seconds with battery disconnected. Return loose parts to the box.