Build Challenges for Level 1 Kits :: MTech: Masterclasses in Technology

⚠️ Small parts! Keep away from small children.

⚠️ Children under 7 should use with adult supervision.

⚠️ To be used with batteries (supplied) and other low voltage sources.

⚠️ Don't put prongs or wires into a wall-socket! Mains sockets have enough voltage and current to injure.

⚠️Don't do electronics with wet or damp hands.

⚠️Don't put items in ears, mouth, nose.

⚠️Put away after use. Don't leave electronic parts lying around where others can step on them, or young children can reach.

Welcome to Electronics! We hope you will have a lot of fun learning and building. Remember to use what you've learnt in the class.

Read the Safety Tips for each part. Apart from those limitations, don't be afraid to try things. You learn by doing, and sometimes it means you might make a mistake and something goes wrong. That's ok! None of these parts are expensive, and you can replenish some or all of them easily and cheaply if one gets damaged - just let us know.

If you get stuck, ask in your next class, or reach out using the inventors email above, or our WhatsApp number.

ENJOY!

What should you do with this kit?

👉Step 1: Unpack Me!

Unpack your kit, count all the parts, and check against the Bill of Materials (the packing list that came with your kit along with the invoice).
Keep at least one bag for the 9V battery. You'll need to always put it away in that bag with nothing else in it and nothing else attached. The rest of the parts you can keep in the plastic container or in their bags.
Browse through the manual for each part to remind yourself about it. All parts will have been discussed and used in your course. The brief text is here to remind you how to use it and any important tips & safety elements.

👉 Step 2: Decide what you want to build

Read the IDEAS TO TRY section for each part in your kit.

Read the Exercises and Challenges section.

👉 Step 3: Try, testing as you go!

Things will not always work the first time. When that happens remember to TRACE your circuit starting from the battery positive wire (red) all the way round to the battery negative wire (black). Read the troubleshooting section of each part and check for common mistakes. Remember you will learn just as much (sometimes more!) when you figure out WHY something wasn't working and what you had to do to get it to work.
Persevere! But if you stay stuck, ask an adult, phone a friend, or reach out to us at MTech. We're happy to to help!

👉 Step 4: Celebrate success!

There's nothing as exhilarating as getting something working! Take a picture. Explain it in a video. Show it to someone. Relish the moment, and then keep going!
Remember to send us your creations on Instagram, our website, or WhatsApp. Each month we will pick from all submissions and giveaway parts!
Watch the Inventors Portal for announcements & competitions.

Let's get building!

Want to showcase your work? You can send us your favourite inventions (picture or video).
If your idea is chosen to be published, you'll be listed as Inventor next to the idea!<br>

MTech: Masterclasses in Technology - www.mathscitech.org - January 2025 - LEVEL 01 CHALLENGES

1. LEDs have polarity, 2. Grabber wires - push to open the hook, attach to metal not plastic insulation, 3. Toggles & Potentiometers are wired by using 2 adjacent pins of the 3 (input, output).

Build Light up an LED
Hints & Tips:
- Remember to use a resistor! If you don't use a resistor, you risk burning out your LED, after which it won't work.
- Remember that an LED has polarity (long leg is +, short leg is -)
- Pro Tip: Bend the SHORT (negative) leg. Then you will know without having to compare leg lengths. (Useful later in electronics, when using breadboards.)
LED with resistor
Experiment Investigate LED Polarity
Investigate:
- What happens when the polarity is wrong? Find out by flipping the LED! Then flip it back.
- Why it matters: this is a common mistake, so if your LED doesn't light up, remember to check polarity.
Explore Exploring LEDs: 5 colors, 3 sizes, steady vs. flashing LEDs,
Steps:
- Build a working LED circuit
- One at a time, swap out the LEDs and try all five colours and the flashing LED. (Remember to respect polarity!)
- Try turning out the lights for each!
- Which colours do you like most?
- Keeping the colour the same, swap out various sizes (10mm, 5mm and 3mm) and see how they each look like when lit. (Remember lights off)
- Pro Tip: Store the flashing LED in its labeled baggie - it is not easy to tell apart the flashing from the white LED
Experiment How many LEDs can you get to light up IN SERIES?
Investigate:
- Use one resistor at the start of the series.
- Connect one LED and light it up
- Now connect the output of one LED to the input of the other, and light them both up.
- Now repeat and keep adding LEDs along the chain, one at a time, and test how many light up.
- Chain along in this way until you run out of wires.
- How many LEDs light up on the same circuit? Do you know why?
- A little theory: Every LED has a 'forward voltage' rating between 1.5V and 3V depending on which colour it is. This decreases the voltage in the circuit by that amount. The circuit starts off with 9V at the battery. Subtracting each time you add an LED means the voltage will for sure drop below the activation volgage, so the next LED won't light up. This is why designers prefer parallel circuits (no limit to number of lights).
LEDs in Series - add one at a time
Invent Parallel circuit for 2 LEDs
Idea:
- Build a single LED circuit, and see it lights up (remember the resistor!)
- Disconnect the battery and snapclip from the first circuit.
- Build a second LED circuit next to the first (use the same battery and snapclip), and see it lights up.
- Where do you see two lights coming on at the same time in real life? (Hint: think about the front of your car...)
- Now commbine them to get a PARALLEL circuit. Here's how: clip the two input ends to the same red battery wire and the two output ends to the same black battery wire.
- If you have unlimited wires and resistors, how would you add more lights to the parallel circuit?
- Where do you see two lights coming on at the same time in real life? (Hint: think about the front of your car...)
Parallel circuit for 2 LEDs
Build Add a latching switch to your single LED circuit
Idea:
- Build a single LED circuit (remember the resistor!)
- Now add a (latching) switch to the start of the circuit, as shown in the diagram below.
- Turn on and off. Works? How fast can you switch?
LED light & switch
Explore Replace the latching switch with momentary switch
Idea:
- Start with the single LED and switch circuit (above)
- Now replace the latching switch with a momentary switch (button switch) as shown in the diagram below.
- Turn on and off. Works? How fast can you switch?
- What's the difference between latching switch (previous build) and momentary switch (this build)?
Application Morse Code Signaling
Learn:
- Use your momentary LED circuit to signal using morse code
Morse code alphabet
Game 2-Player Morse Code Messaging
Game Setup:
- Build the same signaling circuit for your friend
- Go to two sides of a dark room, or one in the garden and one in an upstairs window (works best at night)
- Can you use morse code to message each other?
Invent Create Your Own Signal Language
Challenge:
- Devise your own signaling language with your friend
- Can you reliably communicate?
- Would it be easier if it were light AND sound (beeps)?
Build Replace the LED with a buzzer
Hints:
- Hint: An active buzzer has polarity -- same convention as LED: long leg is +
- Hint: An active buzzer has a built-in resistor, so you can replace BOTH the resistor AND the LED with the buzzer
LED with Dimmer
Application Reversing Truck Simulator
Idea:
- Add a momentary switch to your buzzer circuit
- Can you simulate the beeping of a reversing truck?
Build Reversing Alarm (Light and Sound)
Steps:
- Can you wire up in parallel a light AND a buzzer?
- Now your reversing truck has both light and sound warning
Reversing Alarm (Light & Sound)
Game Reflex Challenge!
Game Setup:
- Build 2 sets of Reversing Alarms
- Have a third person (referee) say "Go!" suddenly
- See which one of you presses the buzzer first (light and sound will fire)
- The slower one becomes the referee. The next waiting player becomes the challenger
- Can you be 'fastest sheriff in the west'?
Experiment Buzzer with Resistor
Investigate:
- What happens when you put a 1K resistor in circuit with the active buzzer?
- Does it sound?
Explore Police Lights Toggle
Hints & Tips:
- What if you wanted to ALTERNATE between red and blue lights, like police lights do?
- This is what a toggle switch is for
- Hint: You just need one resistor, since current is only going through one LED at a time
- Hint: take input flow into the middle pin of the toggle. Connect each end pin of the toggle to the input (positive) pin of an LED
Police Light (Toggle)
2-Player Game Light Beats
Idea:
- Build two sets of police light toggles connected to the same 9V battery
- Pick some rhythmic music (try Believer, by Imagine Dragons).
- Both of you coordinate your flicking of the lights to the beats and to each other
- Get creative with different coloured LEDs and doing different things in time to the music
- Tip: Remember to turn the overhead lights off for best effect!
Build Police Lights & Siren
Idea:
- Build your toggle police lights (above)
- Challenge: can you think how to add the siren so that it always sounds, regardless of whether the toggle selcts red or blue?
Police Light & Siren
Design Challenge Police Lights & Siren with Masterswitch
Idea:
- The police circuit shown can work silently (lights only) if
- Challenge: What if the police chief wanted a design where the siren comes on whenever the lights come on, and whole thing could be shut on fully?
- Tip: Think about where you place your switch
- Insight: As you progress in electronics, you'll be able to build your own real oscillating siren, including tuneable frequencies (distinct nee and naw)!
Police Light & Siren with Masterswitch
Build An Dimmer Control for your LED
Hints & Tips:
- Wire up a rotary potentiometer (variable resistance)
- Hint: Wire it like the toggle, one center pin and one rotary edge pin
- Hint: You need to keep the fixed resistor in the circuit because when the knob is twisted to max brightness, its resistance is 0, so nothing would be protecting the LED if you didn't have the fixed resistor
- Twist the knob back and forward. Is the brightness of the LED changing? You've built a dimmer switch!
LED with Dimmer
Explore Volume Control for Buzzer
Investigate:
- Replace the LED & fixed resistor with buzzer
- What happens when you twist the dial back and forth?
- You've built a volume control, like for a car stereo
Invent Extend your toys!
Ideas:
- Create a street lamp for your cars or figures
- Wire up laser guns for your action figures, with a momentary switch to fire them
- Wire up headlights for your cars with a latching switch to turn them on and off
- Wire up police lights and siren for a police car
- Lots more you can dream up! Send us pictures or videos of your favourite creations!
Build Dimmable Night Light
Steps:
- Create a dimmable night light for your room
- Have a switch so you can turn it on and off
- Use a dimmer to control the brightness
Build Halloween Pumpkin Light
Idea:
- Create a pumpkin light with red LED for Halloween
Build Christmas Tree Star
Idea:
- Illuminate the star at the top of your Xmas tree with an LED
- Pro-Tip: Use the Flashing LED for best effect!
Build Christmas Lights
Idea:
- Wire up as many LEDs as you can in PARALLEL.
- Hint: First build it with 3 LEDs to be sure you've got it right. Then with some ingenuity (see hint below) you can do 4 LEDs with 12 grabber wires (challenge!)
- Pro-Tip: Use the Flashing LED for best effect!
- Hint: You can go from the negative leg of one LED to the negative leg of another, daisy-chaining to the last one which connects back to the negative wire of the snap clip. (This frees up 1 grabber)
Christmas Lights
Build Christmas Lights - Flashing
Idea:
- Add in a momentary switch to the Lights you have built above. This allows you to create flashing light effects!
- Hint: First build it with 3 LEDs to be sure you've got it right. Then with some ingenuity (see hints below) you can do 4 LEDs with 12 grabber wires (challenge!)
- Pro-Tip: Use the Flashing LED for best effect!
- Hint: You can go from the negative leg of one LED to the negative leg of another, daisy-chaining to the last one which connects back to the negative wire of the snap clip. (This frees up 1 grabber)
- Hint: A grabber can grab two legs of a resistor firmly. (This frees up 1 grabber per pair of resistors)
Build Illuminated Artwork
Idea:
- Create some artwork (e.g. drawing a streetlight) using some cardstock and illuminate it with an LED with the wiring and battery hidden behind the paper
Game Marco Polo
Game Setup:
- Build a buzzer circuit with a momentary switch and hide
- Whenever the person seeking shouts 'Marco!', the person hiding has to momentarily sound their buzzer
- With three players (2 buzzers) it gets much harder, because it's not easy to separate pure-tone signals and tell where they're coming from
Game Quiz Master
Game Setup:
- Wire up the quiz buzzer system. To sound the buzzer requires a coordinated move: flip the toggle switch and then press the buzzer
- The toggle switch will light up the LED. The buzzer will ONLY sound when the light is on
- Wire up 2 sets, one with a red LED and one with a blue LED
- This will make it easier for the 3rd player (the Quiz master) to see who was first
- A round is 5 questions. Swap with the referee every round
Quiz Master
Build Colour Mixer
Steps:
- Wire up the RGB Colour Mixing board. GND (-) goes to negative wire of the snap clip.
- Each colour pin (R, G, B) gets wired to a fixed 1K resistor to protect its downstream LED.
- Each resistor connects to a potentiometer. Make sure to match the value of the pot per the diagram
- The pots connect to 9V (red wire of the snap clip)
- Hint: Push down the colour knob onto the shaft after physically setting it to its midpoint.
- Use: Adjusting the dials will mix colours
Colour Mixer

Want to showcase your work? You can send us your favourite inventions (picture or video). If your idea is chosen to be published, you'll be listed as Inventor next to the idea!