CIRCUITS · ELECTRONICS · SIGNALS · PHYSICS · MATH

Learn electronics the way engineers do

Spark Chamber is an in-depth course in circuits and electronics, including the physics and math behind them. Every topic is a node on one tree. You light a topic by proving you understand it, and you keep it lit by reviewing it.

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It's free during Early Access, needs no account, and keeps your progress on your device.

Center: charge, voltage, and current. Outward: what builds on them.

01 · THE TREE

One tree, from the fundamentals up

Topics build from charge, voltage, and current into circuit analysis and electronics. Every line between two topics marks a real prerequisite, so you always know why a topic is locked and what it leads to.

Dark

You haven't unlocked this topic yet, but you can see it and where the subject leads.

Ready

All its prerequisites are lit, so you can start it now.

Lit

You've mastered it: five correct answers in a row, without hints, each harder than the last.

Review due

Lit topics come back for review after 1, 3, 7, 14, and 30 days. If you miss two reviews in a row, you have to master the topic again.

02 · REAL WORK

Design to a spec, with real parts

Design problems give you a requirement and a range of standard part values. The app accepts any design that meets the requirement, not just one textbook answer. It runs some designs in a circuit simulator, so real effects such as op-amp bandwidth or an actual diode drop decide whether your design works.

  • Standard part values from the E12 and E24 series
  • Worst-case analysis with part tolerances
  • Datasheet limits: absolute maximum and recommended operating ratings
  • Designs checked in a circuit simulator
  • The Bench: wire a circuit, predict a reading, and measure it with a multimeter, an oscilloscope, a function generator, or a Bode plotter
  • Hidden faults to find with the meter, on circuits from the problems or your own
  • Circuits you can export to LTspice

Nothing explodes. If your design works only on paper, the feedback names the effect you missed.

DESIGN PROBLEMDIVIDERS
Voltage divider from a 12 V supply
Source12 V Output3.0 V, within 5% PartsR1, R2 from E24, 1 kΩ to 100 kΩ Your answerR1 30 kΩ · R2 10 kΩ Result3.00 V · accepted
WORST CASETOLERANCES
Circuit12 V · R1 3.9 kΩ · R2 1.2 kΩ, ±5% Nominal2.82 V Highest3.05 V (R2 +5%, R1 −5%) Lowest2.61 V (R2 −5%, R1 +5%)
+7.9% Both tolerances push the ratio in the same direction, so the output can shift by more than 5%.

03 · CORRECTNESS

Correct, or it doesn't ship

A wrong answer does more harm than a missing topic, so Spark Chamber checks every problem before you see it.

ComputedAnswers come from formulas. None are typed in by hand.
TestedEach problem type has a test against an answer worked out by hand.
Cross-checkedThe built-in simulator solves some circuit problems a second way, as an independent check.
ReviewedEach topic is reviewed against the sources it cites.

Found a mistake anyway? Use the Report a problem button under the problem. We read every report.

04 · WHAT'S IN IT

From charge to transistors, with more planned

Circuits Electronics Digital logic Signal processing Math Physics Particle physics

Early Access covers circuits and electronics: 50 topics, from charge and current to op amps, diodes, transistors, and MOSFETs, plus reading schematics and SPICE modeling. The other subjects are planned. Each one ships only after it's written, checked, and reviewed.

05 · SUPPORT

Free during Early Access

Every topic, problem, and tool is free while Spark Chamber is in Early Access. There are no ads or subscriptions, and Spark Chamber collects no data to sell. If you find it useful, you can help fund its development.

Support Spark Chamber Support is optional and goes through Ko-fi. It isn't tax-deductible.