Electricity Lab
Batteries, meters, bulbs, and rheostats on a modeled DC and AC bench. Inspect numerical results governed by the simulator’s circuit equations, safely separated from mains hardware.
Domain-specific models · no install · free to start
See electricity become computation.
Wire a battery to a bulb, operate a modeled relay, clock a CPU, or sweep a filter. Each browser lab uses a simulation model appropriate to its subject.
No account to start · 7 languages · modern desktop browser
Two switches in series · lamp = A ∧ BTwo switches in series only light the lamp when both are closed. That is AND. Flip one; the lamp answers.
Open in Relay Lab4labs · open without an account
344published course items · three courses
59free lessons
7languages
counts render from the live catalog
Four labs
Choose a lab.
Every lab opens without an account. Each has a purpose-built workspace and simulation model; one account connects supported services across the platform.
Relay Lab
Modeled coils, contacts, pickup thresholds, and actuation delays support latches, relay logic, and arithmetic on a resistive DC network solver.
Digital Logic Lab
Gates, flip-flops, counters, registers, RAM, and an 8-bit ALU, with inspectable simulator timing and explicit digital states, through to a CPU.
Analog Lab
Op-amps, filters, diodes and transistors on a Rust engine compiled to WebAssembly. Five analysis modes return operating-point values, time-domain traces or frequency-domain plots as appropriate.
One path from physical law to a working computer.
How the labs connect01 · ElectricityPhysical laws, apparatus and measurement.
02 · RelayElectromechanical control and visible logic.
03 · LogicDigital systems, memory, processors, computers.
Branch · AnalogContinuous signals: filters, power, amplifiers, oscillators.
Released Cast learning
Lessons that don’t just play. They teach.
SimCast came first. Published Logic, Relay, and Electricity courses now provide their own Cast experiences. AnaCast has three guided pilots within the eight Analog starters; a full Analog curriculum is not published. Each supported player runs its activity against a live circuit: pause the narration, interact with the circuit, inspect its state, then continue.
SimCast prepares the circuit and drives narration, camera, highlights and learner actions. RelayCast and EleCast share one guided player with captions, hints, action waits and post-lesson exploration.
SimCast
Digital Logic Lab98 lessons · 22 freeNarration, camera moves, highlights and learner actions on a prepared circuit.
RelayCast
Relay Lab102 course items · 18 freeGuided player with captions, hints, action waits and post-lesson exploration.
EleCast
Electricity Lab144 experiments · 19 freeThe same guided player, on a bench of meters, bulbs, supplies and scopes.
AnaCast
Analog Lab4 example groups · 8 verified startersThree guided AnaCast pilots explore RC filtering, half-wave rectification, and a common-emitter amplifier. A full Analog curriculum is not published.
A recurring learning cycle
- 01 · BuildPlace a battery, a switch, a relay, a lamp.
- 02 · MeasureRead the meter: 6.0 V across the coil.
- 03 · PredictWhat happens to the lamp when the contact flips?
- 04 · VerifyFlip the switch. The circuit answers for itself.
Start a free lesson59 free · 344 published · 7 languages
Keep your work
Circuits and progress, across devices.
With a free account, supported cloud saves and lesson progress remain linked to your sign-in. Storage and sharing features vary by lab and plan.
Create a free accountShare & embed
Embed live circuits on supported webpages.
Supported Logic templates and Relay Blueprints embed as responsive iframes. These are interactive circuit models rather than static screenshots.
Embed snippet
Browse circuits to embed <iframe src="https://digisim.io/circuits/embed/template/and-gate-security-system?theme=dark" width="100%" height="480" allow="fullscreen"></iframe>Teach with it
Demos, public lessons and embeds today.
Classroom, with sections, seats and assignments, is coming soon. Join the educator waitlist and use the free resources now.
Plans
Start free. Upgrade when you need the whole bench.
Free$0All four labs, core component sets, 59 free lessons. No card.Profrom $6/moThe complete current component catalog and all 344 published course items, subject to each lab’s supported workflows. $58 a year.Founder$99onceEverything in Pro for one payment, while the offer lasts.Start checkout by December 31, 2026 at 23:59:59 UTC.ClassroomComing soonSeats and sections for schools. No price until release. Educator waitlist open.
Compare plans A supported, verified school email on your account is required for the automatic 50% education discount at checkout.
Start with one relay. Build toward a computer.
No account or installation is required to open the Relay Lab and place the first relay.