Electronics basics
A breadboard and a few parts, with one Uno blink at the start and no processor after it. What current, voltage, time and logic really do.
Open the courseAll courses
Electrical track
Electronics, from your first LED to a computer you built from gates
Current and voltage you can see, then transistors, op-amps, filters, power and PCBs. Every circuit runs in a real circuit simulator in your browser.
The track
Zero to expert, one course at a time
This is the electronics underneath everything else on Mokxi: what current, voltage, resistance and time really do in a circuit. You build each circuit on a simulated breadboard, measure it with a meter or a scope, and the simulator checks the result.
It starts from nothing, with a loop you wire by hand, and climbs through the circuits engineers use every day: dividers, RC timing, transistors, op-amps, rectifiers and regulators, filters and frequency response, then logic from a single NAND gate up to a working CPU, and finally a board ready for manufacturing.
The ladder
Every course, by level
Take them in order, or start on the rung that matches what you already know. Each course page lists every lesson.
Level 1
Start from zero
A breadboard, a few parts and what they really do.
Digital logic and memory
Build logic from individual gates, then make a bit persist, count and move through a register.
Open the courseLevel 2
Real circuits
Amplifiers, power, sensors and switching bigger loads.
Transistors and op-amps for real
Intermediate, after Electronics basics: the diode curve, biasing a BJT, common-emitter gain, the MOSFET as switch and resistor, op-amp gain both ways, comparators with hysteresis and split supplies.
Open the coursePower and batteries
Where the volts come from and how to keep them: Ohm's law on a real meter, cells in series and parallel, a regulator, a LiPo on a TP4056, a boost converter, a battery gauge, and a power bank you build yourself.
Open the courseSensors and measurement
Intermediate: thermistors and RTDs, strain gauges in a Wheatstone bridge, light and IR, current on a shunt and an INA219, ADC resolution and noise, and calibration, finished with a power instrument you check against Ohm's law.
Open the courseRelays, contactors and motor control
Intermediate, the electrician's course: relay coils and flyback diodes, latching start/stop circuits, interlocks, three-way switching, timers and ladder logic, all at low voltage, finished with a start/stop station and an emergency stop you wire yourself.
Open the courseLevel 3
Go deeper
Signals and filters, a CPU from gates and a board of your own.
AC, signals and filters
Advanced, after Transistors and op-amps for real: sine, peak and RMS, reading a scope, RC and RL filters, frequency response, RLC resonance and active filters.
Open the courseFrom gates to a computer
Start with one NAND gate, package every circuit you build into a chip, and use your chips to build the next one: an adder, memory, a CPU of your own, and a computer that runs your program.
Open the courseBreadboard to PCB
Take three working circuits from the breadboard to a finished board: the schematic, footprints, placement, routing, design rules, and what a board house needs.
Open the courseLevel 4
Expert
Switching power and a full design from requirement to board.
Power electronics
Advanced: switches, inductors and heat: buck and boost converters from loose parts, PWM, MOSFET drivers, H bridges, efficiency, and a regulated supply you set from its formula.
Open the courseCircuit design capstone
Expert: take one product from a written requirement to a tested board: blocks, a schematic worked out on paper, part choice, simulating the corners, PCB layout, a test plan, and a revision that fixes what the tests found.
Open the courseOutcomes
What you will be able to do
- Use Ohm's law, dividers and RC time constants to choose real part values.
- Bias a transistor, set an op-amp's gain and build comparators and filters.
- Design a supply with a rectifier, a regulator or a boost converter, and charge a LiPo safely.
- Build logic from NAND gates up to an ALU, memory and a CPU, and lay out a PCB.
Careers
Where this track leads
The jobs these skills are used in every day, with what each one does and how to get there.
Electronics technician
Test, repair and build circuit boards and the gear they live in.
See the careerElectrician
Wire homes and factories safely: circuits, relays, contactors and motor control.
See the careerElectrical and hardware engineer
Design the circuits and boards that new products are made of.
See the careerRobotics and automation technician
Build, wire, program and fix the robots and machines in real factories.
See the careerTopics
Looking for something specific?
Each of these starts you on the right course and lesson for one subject.
A digital logic course, from gates to memory to a CPU
Gates as real chips, a latch that remembers, flip-flops that count and a shift register, then adders, an ALU, RAM and a CPU built from one NAND gate.
Start hereTransistors and op-amps, for real
The diode curve, biasing a BJT, common-emitter gain, MOSFETs as switches and resistors, op-amp amplifiers, comparators with hysteresis and split supplies.
Start hereAC, signals and filters you can see on a scope
Sine, peak and RMS, reading a scope, RC low-pass, high-pass and band-pass, frequency response, RLC resonance and active filters.
Start herePower supply design: from the wall to a battery pack
Rectifiers and smoothing, linear regulators, a boost converter, LiPo charging and a battery gauge, each one measured on simulated meters.
Start hereLearn PCB design: from a working breadboard to Gerbers
The schematic, footprints, placement, routing, design rules and the Gerbers and BOM a board house needs, on three circuits that already work.
Start hereThe multimeter, the oscilloscope and the logic analyzer, on real faults
Volts across and amps through, the power-off checks, PWM and bounce on a scope, a logic probe and analyzer, then one circuit with three bugs.
Start hereElectrician training online: the circuit skills, free
Practice the electrical theory part of the trade: Ohm's law with a real meter, series and parallel, relays, rectifiers and the power-off checks, in a simulator.
Start hereElectronics for programmers
You already think in state, timing and interfaces. This route maps them onto current, voltage, pull-ups and buses, with code you can read on a simulator that shows each wire.
Start hereQuestions
About the electrical track
Can I learn electronics online for free?
Yes. Every course in this track is free and runs in your browser, with a circuit simulator that measures voltages and currents the way a real meter and scope would.
Do I need math to learn electronics?
Only arithmetic to start. Ohm's law is one multiplication, and the lessons show the numbers on a meter as you go. The later courses use a little algebra for gain and filters, explained when it comes up.
Is this the same as an electrical engineering degree?
No, but it covers the circuits a first and second year of one does, hands-on, so it is good preparation for a degree, a technician job or your own projects.
Do I need parts or a kit?
No. Every circuit is built on a simulated breadboard. When you want to build one for real, the same parts and wiring work on a bench.
Tracks
The other tracks
Coding track
Python and C++ from your first print to classes, tests and state machines. Every program runs on a simulated board, so a bug is something you can see.
See the trackEmbedded track
Arduino, ESP32, Raspberry Pi Pico and STM32: pins, timing, buses, motors, WiFi, registers and debugging, every lesson checked on a simulated board.
See the trackMaker track
Follow the starter kit you already own, then build a claw machine, a balance bot, a handheld console or an LED cube, each a short course checked by the simulator.
See the trackRobotics track
Motors, servos, sensors and PID control loops, then a rover, a claw machine and a balance bot, every lesson checked on a simulated board.
See the track