5 Electronics Projects Kids Can Build for Under $20

You don't need an expensive kit to get into electronics. With a few cheap parts and some adult help, kids can build real circuits that light up, buzz, and move. Here are five small projects, each well under $20.

What can you build for under $20?

Most of these use the same handful of parts: a battery holder, some wire, an LED (a tiny light), a buzzer, and maybe a small motor. Buy them once and you can mix and match for ages.

Project	What it does	Key parts
LED light-up badge	A tiny light you can wear	LED, coin battery, tape
Simple buzzer doorbell	Press a button, it beeps	Buzzer, button, battery
Pocket torch	A switch turns a light on and off	LED, switch, battery
Brush-bot	A toothbrush-head robot that wobbles	Small motor, coin battery, brush head
Paper circuit card	A greeting card that glows	Copper tape, LED, coin battery

Project 1: LED light-up badge

Press the two legs of an LED onto a coin battery and it lights up. Tape it in place and you have a wearable badge. This is the gentlest way to see a circuit work.

Safety note: Adults should keep coin batteries away from little ones, as they are dangerous if swallowed. Low-voltage batteries only.

Project 2: Simple buzzer doorbell

Connect a battery, a push-button, and a small buzzer in a loop. When you press the button, the loop closes and the buzzer sounds. It is a clear, noisy way to learn what a switch does.

Safety note: Use a low-voltage battery (around 3 to 6 volts) and have an adult check the connections before powering up.

Project 3: Pocket torch

Add a small slide switch between the battery and the LED. Now you can turn the light on and off, just like a real torch. It teaches the idea of controlling a circuit.

Safety note: Adult supervision, low-voltage only. Never connect a battery's two ends straight together (a short circuit) as it can get hot.

Project 4: Brush-bot

Tape a tiny motor and a coin battery onto a toothbrush head. The spinning motor makes it shake and scoot across the table. It is a first taste of how robots move.

Safety note: An adult should help with the motor and battery. Keep fingers and hair away from the spinning part.

Project 5: Paper circuit card

Stick copper tape on paper to make a path, add an LED and a coin battery, and fold the card to switch it on. A lovely, quiet project that hides real electronics inside art.

Safety note: Low-voltage coin battery only, with an adult nearby. These projects use small batteries, never mains power from a wall socket.

How do kids learn the why behind it?

Building is fun, but understanding why a circuit works makes it stick. In Incendio's live online electronics classes for kids, working engineers guide kids through real components step by step, so they learn what each part does and how to fix it when it doesn't light up.

Curious to go further with a friendly engineer? You can enrol in a beginner-friendly class whenever you're ready.

Frequently asked questions

Are these projects safe for kids?

Yes, when an adult helps. Every project here uses low-voltage batteries, never mains power from a wall socket. Keep coin batteries away from small children, as they are dangerous if swallowed, and have an adult check connections before switching anything on.

What parts do I need to buy first?

Start with a coin battery, a couple of LEDs, some copper or sticky tape, and a small buzzer or motor. These cost only a few dollars and cover most beginner projects. A simple battery holder and a switch are handy next steps.

Does my child need to know how to code first?

No. These projects are pure hands-on electronics, with no coding required. They are a great first step because kids can see and hear the result straight away. Coding and robotics can come later, building on the same basic circuit ideas.