Hands-On Electronics
Demystify how everyday gadgets work by building and understanding circuits from the ground up. Learn to direct electrical currents, wire components safely, and read circuit behaviors.
Like Duolingo, but for Hands-On Electronics. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
28 levels across 4 sections, about 56 minutes end to end, roughly 11 days at five minutes a day. It moves through The Closed Loop, Controlling the Current, Switching and Sensing, and Integrated Systems and Troubleshooting. It starts from scratch.
Free forever · No credit card · iPhone & Android

Key ideas in Hands-On Electronics
- Electricity must complete a full, continuous loop from the power source back to ground to flow
- A gap anywhere in the circuit halts the flow of electricity to all components in that loop
- Voltage is the electrical pressure that pushes charge through conductors
- Higher voltage provides more push to move charge through circuit components
- Current measures how much electrical charge actually flows past a point per second
- Voltage is the push that creates current, but current is the flow itself
- LEDs are directional (polarized) and only allow current to pass in one direction
- The longer leg must connect toward the positive power side and the shorter toward negative/ground
- Flipping the LED 180 degrees reverses its orientation so current can flow
- A short circuit happens when electricity takes an unintended path that skips the load entirely
- Without resistance to slow the flow, an enormous surge of current generates rapid, dangerous heat
- The battery and wire can become hot enough to melt plastic or burn fingers
- Breadboard holes grip wires using internal spring tension rather than permanent solder
- Parts can be repeatedly plugged in, unplugged, and rearranged without damaging them
- Outer power rails (often marked red and blue) run power vertically along the entire side
- Numbered rows in the middle connect five adjacent pins horizontally into a single node
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 Hands-On Electronics 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.
What happens to the components in a circuit if a single wire is unplugged, creating an open gap?
Get it right to open this lesson and 27 more in the app.
Where Hands-On Electronics takes you
- 1
The Closed Loop
- Making Your First Circuit Work
- Prototyping on a Breadboard
- 2
Controlling the Current
- Protecting Circuits with Resistors
- Storing Energy in Capacitors
- Directing Current with Diodes
- 3
Switching and Sensing
- Switching with Transistors
- Interfacing with Sensors
- 4
Integrated Systems and Troubleshooting
- Logic and Integrated Circuits
- Finding and Fixing Circuit Faults
4 sections · 9 units · 28 levels. Built to play, not to enroll.
You pick the voice
Hands-On Electronics is taught in the 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.
More Technology on Tomo
How Electric Circuits Work
Learn how electricity moves through everyday devices and gain the confidence to build your own circuits. From breadboarding components to debugging with a multimeter, discover the practical rules that bring hardware to life.
Mastering the Flow: Practical Electronics
Move beyond simple batteries and bulbs to design circuits that solve real problems. Master the math of power, troubleshoot like a pro, and understand how modern gadgets actually think.
The Flow of Power: Basic Circuits
Stop guessing and start building. Learn to direct the invisible force of electricity to power lights, motors, and your own inventions.
Electricity and Practical Circuits
Move beyond basic textbook formulas to build a working intuition for real circuits. Learn how components behave under load, diagnose tricky faults, and master the forces shaping electrical systems.
How Electronics and Sensors Work
Discover how tiny electrical currents are tamed to measure the physical world. Build an intuitive mental model of circuits, sensors, and the quantum physics powering modern silicon chips.
Practical Electronics: From Circuits to Chips
Learn how electricity is harnessed, amplified, and programmed to power modern hardware. Explore real-world circuits from basic LEDs and transistors up to microcontrollers, op-amps, and commercial silicon chips.
Start Hands-On Electronics today.
Download Tomo, search Hands-On Electronics, and play your first lesson in under a minute.