TechnologyThe ProfessorIntermediate
Practical Circuit Design, a free technology course 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.

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.

21 levels across 3 sections, about 42 minutes end to end, roughly 8 days at five minutes a day. It moves through Active Switching and Amplification, Conditioning Signals and Regulating Power, and Building Reliable Physical Systems. It assumes you already know the basics.

21 bite-size levelsAbout 5 minutes each

Free forever · No credit card · iPhone & Android

Farad the Fox, the guide who teaches the Practical Circuit Design course
Practical Circuit Design
with Farad the Fox
21
Levels
3
Sections
5
Min/day
What you'll learn

Key ideas in Practical Circuit Design

  • Inadequate base current leaves a BJT in its linear region with high voltage drop.
  • Driving a BJT into hard saturation drops Vce to around 0.2V, minimizing heat.
  • Decreasing the base resistor value delivers the extra current needed to saturate.
  • Vgs(th) marks only where conduction starts, typically at tiny microamp currents.
  • Standard power MOSFETs need 10V at the gate to achieve minimum channel resistance.
  • Logic-level MOSFETs specify their full Rds(on) rating at 3.3V or 5V gate drives.
  • Collapsing magnetic fields reverse inductive voltage and create large spikes.
  • A flyback diode connects in reverse bias, with its cathode on the positive rail.
  • The diode clamps the inductive kickback voltage before it exceeds transistor Vce.
  • Low-side switches sit between load and ground, floating the load ground when off.
  • High-side switches sit between power and load, keeping ground reference intact.
  • Microcontroller GPIO pins default to high-impedance inputs during boot and reset.
  • MOSFET gates behave like tiny capacitors that trap charge and drift into conduction.
  • A pull-down bleeds trapped charge to ground, guaranteeing the switch stays off.
  • Negative feedback routes part of the output back to the inverting input.
  • High open-loop gain forces the differential input voltage toward zero.
Why not just Google it

You've tried the other tabs

Wikipedia

Thirty open tabs. Four facts you actually kept.

YouTube

You watched. You nodded. By Sunday it was gone.

ChatGPT

One answer, then back to scrolling.

Online courses

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.

Try a question

Here's what playing it feels like

A real question from this course. Take your best guess.

Switching Loads with Clean Control

What happens to a BJT's collector-emitter voltage (Vce) when you drive it into hard saturation?

Get it right to open this lesson and 20 more in the app.

Course map

How to learn Practical Circuit Design, step by step

Go in order. 21 short levels across 3 sections, about 42 minutes in all, five minutes a day.

  1. 1

    Active Switching and Amplification

    • Driving Loads with Transistors
    • Harnessing Operational Amplifiers
  2. 2

    Conditioning Signals and Regulating Power

    • Filtering and Shaping Signals
    • Regulating Power and Managing Heat
  3. 3

    Building Reliable Physical Systems

    • Interfacing Sensors to Microcontrollers
    • Taming Noise, Grounding, and Parasitics
    • Diagnostic Bench Testing and Signal Tracing

3 sections · 7 units · 21 levels. Built to play, not to enroll.

Questions

Questions about Practical Circuit Design

  1. How do I learn Practical Circuit Design?

    Go in order: start with Active Switching and Amplification, then Conditioning Signals and Regulating Power, then Building Reliable Physical Systems. On Tomo that's 21 short levels, about 42 minutes in all, played five minutes a day. Start free and play the first level in under a minute.

  2. Is there a Duolingo-style app for Practical Circuit Design?

    Yes. Tomo works like Duolingo: short daily lessons, streaks and quick quizzes. Practical Circuit Design is one of its free courses, and you can type any other topic to get a course of your own.

  3. Is the Practical Circuit Design course free?

    Yes. Practical Circuit Design is playable on Tomo's free plan, which doesn't expire. No credit card, no waitlist. Download the app and start your first lesson.

  4. How long does it take to learn Practical Circuit Design?

    21 levels across 3 sections, about 42 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.

  5. Do I need any background to start Practical Circuit Design?

    No. It's pitched at an intermediate level, so it starts where you are and builds up. If you can tap a phone, you can start.

New

Tomo is in ChatGPT

Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.

Add Tomo to ChatGPT
How it's taught

You pick the voice

This course
The Professor

Practical Circuit Design 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.

Keep going

More Technology on Tomo

Designing Electronic Systems course icon

Designing Electronic Systems

Bestie

Bridge the gap between simple breadboard circuits and robust, functional hardware systems. Learn how to condition analog signals, manage power and switching loads, coordinate noisy digital communication, and track down real-world hardware bugs.

24 levels48mIntermediate
Building Working Circuits course icon

Building Working Circuits

Professor

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.

29 levels58mIntermediate
Audio Electronics: Sculpting Sound course icon

Audio Electronics: Sculpting Sound

Bestie

Move beyond basic circuits to understand how electricity becomes music. Learn to manipulate signals, design filters, and master the art of clean amplification.

10 levels20mIntermediate
Real-World Circuit Design course icon

Real-World Circuit Design

Bestie

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.

26 levels52mAdvanced
Circuit Design for Arduino course icon

Circuit Design for Arduino

Professor

Bridge the gap between microcontroller code and reliable hardware. Learn how to drive high-power loads, clean up noisy sensor readings, stabilize power delivery, and protect components from catastrophic damage.

24 levels48mIntermediate
Electricity and Practical Circuits course icon

Electricity and Practical Circuits

Professor

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.

22 levels44mIntermediate
Start free

Start Practical Circuit Design today.

Download Tomo, search Practical Circuit Design, and play your first lesson in under a minute.