Building Your First Circuits
Demystify hardware by learning how real electricity behaves in wires, components, and boards. Move from lighting your first LED safely to switching power with transistors and diagnosing broken circuits with confidence.
Like Duolingo, but for Building Your First Circuits. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
A short one: 12 levels across 2 sections, about 24 minutes end to end, roughly 5 days at five minutes a day. It moves through Making Current Flow and Behave and Switching, Storing, and Troubleshooting. It starts from scratch.
Free forever · No credit card · iPhone & Android
Key ideas in Building Your First Circuits
- Electricity only flows when there is an unbroken loop from the power source and back to it
- A single wire going into a component without a return path leaves the circuit open, so no current can move
- LEDs and batteries have polarity: they only function properly when oriented in the correct direction
- Resistors are non-polarized: they restrict current identically in either orientation
- An active LED offers almost zero resistance to electricity
- Without a resistor to choke the flow, an overwhelming rush of current burns out the LED almost instantly
- Voltage is the electrical push or pressure supplied by the power source
- Current is the actual volume or rate of electrons flowing through the path
- The battery's voltage stays constant while the resistance of the path controls how much current actually flows
- Current always takes the path of least resistance
- A direct connection between power and ground with zero resistance creates a short circuit, causing massive current flow and rapid heating
- Resistors arranged in series line up along a single path, so their resistance values add together
- A higher total resistance in a circuit reduces the overall flow of current from a fixed voltage source
- Series components share and divide the total battery voltage among themselves
- In a parallel circuit, each branch connects directly across the full supply voltage
- Current flows through each parallel path independently, so breaking one branch does not stop current in neighboring branches
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Building Your First Circuits the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
You connect one wire from a battery's positive end to an LED, but leave the other end disconnected. What happens?
Get it right to open this lesson and 11 more in the app.
How to learn Building Your First Circuits, step by step
Go in order. 12 short levels across 2 sections, about 24 minutes in all, five minutes a day.
- 1
Making Current Flow and Behave
- Lighting an LED Without Frying It
- Directing Current with Resistors and Switches
- 2
Switching, Storing, and Troubleshooting
- Automating Actions with Capacitors and Transistors
- Diagnosing Faults with a Multimeter
2 sections · 4 units · 12 levels. Built to play, not to enroll.
Questions about Building Your First Circuits
How do I learn Building Your First Circuits?
Go in order: start with Making Current Flow and Behave, then Switching, Storing, and Troubleshooting. On Tomo that's 12 short levels, about 24 minutes in all, played five minutes a day. Start free and play the first level in under a minute.
Is there a Duolingo-style app for Building Your First Circuits?
Yes. Tomo works like Duolingo: short daily lessons, streaks and quick quizzes. Building Your First Circuits is one of its free courses, and you can type any other topic to get a course of your own.
Is the Building Your First Circuits course free?
Yes. Building Your First Circuits is playable on Tomo's free plan, which doesn't expire. No credit card, no waitlist. Download the app and start your first lesson.
How long does it take to learn Building Your First Circuits?
12 levels across 2 sections, about 24 minutes of play in total. It's built for five minutes a day, so you finish it a little at a time instead of all at once.
Do I need any background to start Building Your First Circuits?
No. It's pitched at a beginner level, so it starts where you are and builds up. If you can tap a phone, you can start.
Tomo is in ChatGPT
Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.
Add Tomo to ChatGPT- What to ask
- “Make me a Tomo course on black holes.” “Turn this chat into a Tomo course.”
- What you get
- Quick questions with instant feedback, hearts and stars, ready to play in about a minute.
- Where it goes
- No sign-up to start. Connect your Tomo account and your streak carries on in the app.
You pick the voice
Building Your First Circuits is taught in the Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
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Start Building Your First Circuits today.
Download Tomo, search Building Your First Circuits, and play your first lesson in under a minute.