Circuits 1 labs without hardware, for college and university
Dividers, series and parallel networks, capacitors, a 555, op-amps and transistors, measured with a meter and a scope in the browser. Checks read node voltages, so the class feature grades a design by its numbers.
Where Mokxi fits
A first circuits course covers Ohm’s law and Kirchhoff’s laws, series and parallel networks, and capacitors and inductors. It often ends with a first look at op-amps and transistors. Each topic has a circuit here that students can build, measure and change.
The analog parts are solved as a real circuit by nodal analysis. The meter loads what it measures, like a real one, and the scope has two channels.
The editor also runs SPICE netlists: operating point, transient, AC, DC sweeps and more. Its engine is checked against ngspice on 42 benchmark circuits.
For graded work, a check reads the voltage of any node. So a design lab, such as a divider that must give 2.5 V, is graded by what it measures.
The labs, by topic
Each row is a topic, the week of the 12-week course that covers it, a circuit that runs now and the pages that explain it.
| Topic | Course week | Lab to open | Read more |
|---|---|---|---|
| Ohm’s law and dividers | Week 1 | A divider, measured | Voltage Dividers and Why They Are Bad Power Supplies · Electrical Circuits Lab Online, With Graded Checks |
| Series and parallel networks | Week 1 | The circuit on the reading page | Series vs Parallel Circuits, Seen With LEDs |
| Capacitors and the RC time constant | Week 4 | RC filter on the bench | The RC Time Constant, on an Oscilloscope |
| RL circuits | Extra lab | RL filter on the scope | |
| RLC resonance | Extra lab | RLC resonance on the bench | |
| Timing with the 555 | Week 4 | 555 blinker | The 555 Astable: Timed by a Capacitor, Not a Crystal |
| Op-amp circuits | Extra lab | Op-amp low pass on the bench | The Non-Inverting Op-Amp Amplifier, on a Scope · An Op-Amp as a Comparator, With Hysteresis |
| Transistors and MOSFETs as switches | Extra lab | MOSFET switch | An NPN Transistor as a Switch, Driving a Motor · MOSFET vs BJT: Which Transistor to Switch With |
Every week has a one-page PDF lesson plan. They are all on the teacher resources page.
Where it does not fit
- It solves circuits, not fields. There is no electromagnetics.
- SPICE decks run without BSIM transistor models, XSPICE devices or distortion analysis. LTspice or ngspice go further for those.
- Parts do not burn out, and a reading has no noise. Students should still use a real meter on a real bench.
Labs you can assign today
Each lab starts from a template in the class page’s Assign work form and comes with checks that grade it. The checks are tested on the simulator against the starter and the answer.
Students use the simulator free. With a school email address, Pro is half price: see the student discount. For a department or a large course, get a written quote.
Questions
Can it replace Multisim Live for our class?
For many labs, yes. It runs in the browser, it is free for students, and it grades work. The comparison page lists the SPICE features it does not have.
Can I grade a design, not only a reading?
Yes. A check reads a node voltage within a tolerance. Two checks on two nodes can require one exact design, like the divider lab on the lab page.
Does it do AC analysis?
Yes. The editor draws a small-signal frequency response as a Bode plot, and SPICE decks can run AC analyses.
More for this course
Setting up a class for a university course · SPICE in the browser · Mokxi and Multisim, compared · Mokxi and LTspice, compared · All the free teacher resources · The 12-week course · IT setup for schools · Chromebook readiness test
Other course pages: High school engineering and CTE: digital electronics · Middle school STEM: first circuits · Intro and AP physics: circuits · College and university: digital logic · College and university: microcontrollers