Practical Circuit Design
Like Duolingo, but for Practical Circuit Design. 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.
24 levels across 4 sections, about 48 minutes end to end, roughly 10 days at five minutes a day. It moves through Active Switching and Control, Clean Signals and Measurement, Bridging Analog and Digital, and Designing for the Real Board. It assumes you already know the basics.
Free forever · No credit card · iPhone & Android
Key ideas in Practical Circuit Design
- GPIO pins typically tap out at 20mA to 40mA and cannot supply high-current actuators
- Driving high-current loads directly damages the microcontroller pin driver circuitry
- Transistors let a tiny milliamp control signal switch amps of external power safely
- BJTs need sufficient base current to achieve full saturation and minimize voltage drop
- An oversized base resistor leaves the BJT in the active region where high resistance creates heat
- Deep saturation drops collector-emitter voltage to around 0.2V, keeping dissipation minimal
- Standard MOSFETs often require 10V at the gate to achieve their lowest on-resistance
- Logic-level MOSFETs reach fully rated Rds(on) with gate voltages as low as 3.3V or 5V
- Undertargeting gate drive leaves the channel partially resistive, starving the load and baking the FET
- Collapsing magnetic fields in coils force current forward, creating massive reverse voltage spikes
- A parallel flyback diode safely recirculates this inductive kickback current until it dissipates
- Without flyback suppression, high voltage arcs exceed the transistor's breakdown rating
- Low-side switching cuts the path to ground and uses standard N-channel devices
- High-side switching cuts the positive supply rail using P-channel or PNP devices
- Chassis-grounded loads like car horns require high-side switches to stay connected to zero volts
- A typical 10-bit ADC has steps around 3.2 mV across a 3.3V reference.
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 Practical Circuit Design 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.
Picture wiring a 500mA solenoid directly to your microcontroller pin. What happens inside the chip when you fire it up?
Get it right to open this lesson and 23 more in the app.
Where Practical Circuit Design takes you
Move past breadboard tutorials to build, analyze, and troubleshoot circuits that operate reliably in the real world. Learn how to control high-power loads, clean up noisy signals, select the right power architecture, and design durable printed circuit boards.
- 1
Active Switching and Control
- Driving Real Loads with Transistors
- Conditioning Sensor Signals with Op-Amps
- 2
Clean Signals and Measurement
- Diagnosing Dynamic Signals with an Oscilloscope
- Taming Noise with Passive Filtering
- 3
Bridging Analog and Digital
- Interfacing Digital Logic with the Real World
- Choosing and Regulating Power Supplies
- 4
Designing for the Real Board
- From Breadboard to PCB Layout
- Systematic Hardware Debugging
4 sections · 8 units · 24 levels. Built to play, not to enroll.
You pick the voice
Practical Circuit Design is taught in the The Storyteller style: every lesson is a story. 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
Practical Circuit Design
Move beyond basic breadboard recipes to design reliable, real-world circuits. Learn to drive high-power loads, shape signals with op-amps, clean up noisy power rails, and debug circuits with confidence.
Building Working Circuits
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.
Embedded Systems: Code Meets Hardware
Bridge the gap between pure software and physical circuits. Learn how to write non-blocking firmware, interface digital sensors over standard buses, safely drive high-power loads, and diagnose hardware bugs.
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.
Real-World Circuit Design
Move past idealized textbook schematics into the physics of high-speed signals, control loop stability, and electromagnetic compliance. Master parasitic management, noise reduction, and robust power delivery.
Electronic Circuit Troubleshooting
Move beyond basic multimeter readings to systematically diagnose and repair complex hardware failures. Learn to isolate faults, interpret signal noise, and reverse engineer circuits without a map.
Start Practical Circuit Design today.
Download Tomo, search Practical Circuit Design, and play your first lesson in under a minute.