Building Working Circuits
Like Duolingo, but for Building Working Circuits. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
For the part of you with thirty open tabs that never became anything.
29 levels across 4 sections, about 58 minutes end to end, roughly 12 days at five minutes a day. It moves through Driving Real-World Loads, Conditioning Analog Signals, Power and Timing Stability, and Bench Diagnostics and Assembly. It assumes you already know the basics.
Free forever · No credit card · iPhone & Android
Key ideas in Building Working Circuits
- Saturating a BJT requires much more base current than active gain predicts
- A common rule of thumb uses an overdrive ratio of ten to one for saturation
- Insufficient base drive traps the BJT in linear mode where it burns heat
- Gate threshold voltage is only where conduction barely starts, not full on
- Datasheets specify RDS(on) test voltages needed to achieve minimal resistance
- Driving standard MOSFETs with 3.3V pins leaves the channel mostly pinched
- N-channel gates must be several volts above the source to conduct
- High-side N-channel sources float near the supply voltage when fully active
- Low-side switches keep the source tied to 0V ground for easy pin control
- A MOSFET gate acts like a discharged capacitor at the moment of switching
- Instantaneous charging draws a burst that can exceed GPIO current limits
- A low-value series component throttles peak current without stalling edge speed
- Transistors burn peak power when high voltage and high current overlap
- Weak gate drive stretches edge transition times across linear mode
- High PWM frequencies multiply the number of lossy transitions per second
- Collapsing magnetic fields in coils generate reverse voltage spikes far exceeding the supply rail.
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 Working 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.
What standard rule of thumb helps ensure a BJT switch enters deep saturation?
Get it right to open this lesson and 28 more in the app.
Where Building Working Circuits takes you
Bridge the gap between textbook schematics and hardware that actually turns on and runs reliably. Learn to select the right components, tame noise and power drops, and diagnose real circuits on the bench.
- 1
Driving Real-World Loads
- Transistors as Solid-State Switches
- Taming Inductive Kickback and Inrush
- 2
Conditioning Analog Signals
- Voltage Dividers and Impedance Loading
- Operational Amplifiers in Practice
- Comparators and Hysteresis
- 3
Power and Timing Stability
- Clean DC Power and Decoupling
- Waveform Generation and Timing
- 4
Bench Diagnostics and Assembly
- Breadboard Parasitics and Assembly Realities
- Systematic Hardware Diagnostics
4 sections · 9 units · 29 levels. Built to play, not to enroll.
You pick the voice
Building Working Circuits 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.
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Start Building Working Circuits today.
Download Tomo, search Building Working Circuits, and play your first lesson in under a minute.