Wonder Circuits vs Learning transistor

Learn digital logic through 62 lessons in 13 chapters. Start with AND, OR and NOT, then build binary adders, feedback circuits, registers, memory and state machines. Assemble a visible four-bit computer and write programs for it. Start with the first 14 lessons and the complete Logic Lab for free. One optional purchase unlocks the remaining 48 lessons and all future core content. No subscriptions or consumables. Build freely in the complete Logic Lab, save reusable chips and share offline blueprints. Works offline, with no accounts, ads or tracking. This is a digital logic simulator; it does not model voltage or current. Campaign lessons still progress in order after purchase.

How does a computer actually compute? Not metaphorically — physically. Learning Transistor answers that question in 14 interactive screens, starting from a single transistor and ending at a working one-bit computer you can step through with your finger. Every screen is a live circuit. Current flows as moving dots, voltage glows on the wires, and every input is yours to flip. Nothing is a video, and nothing is a quiz — you learn by turning things on and off and watching what the electrons do. THE JOURNEY - Meet Transistor Man — the classic mental model of how a transistor keeps its collector current exactly 100 times the base current, and what happens when it can't - The transistor switch: how 9.4 mA of base current lights a 100 mA lamp - The NOT gate: how a resistor and a transistor turn voltage into logic — and why "1" costs no current at all - NAND and NOR at the transistor level: series vs parallel, and why these two gates can build everything else - The symbol language: the D-shape, the pointed shape, and the little circle that flips every answer - Building with gates: AND from NANDs — abstraction you can tap to open and see the transistors still working inside - The SR latch: two crossed gates that remember one bit after your finger leaves the screen - XOR and the half adder: the moment logic becomes arithmetic, and 1 + 1 becomes 10 - The finale: memory + adder + feedback + a STEP clock — a one-bit computer, with every layer tappable all the way down to the silicon FREE TO START The first two screens — Transistor Man and the transistor switch — are free. A single purchase unlocks the rest of the journey. No subscriptions, no ads, no accounts, no data collection. Inspired by the classic figures of The Art of Electronics. Made for curious minds who want to know what is really happening inside the machine they are holding.