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All courses15-part course

Electricity Fundamentals

A free 15-lesson course for anyone curious about electricity, built around surprising facts: why the light comes on instantly, why birds don't get shocked, how a phone charger changes the electricity twice. No science background needed.

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Foundations

  1. 1

    What Is Electricity, Actually?

    Inside a wire, electrons drift a fraction of a millimetre per second, yet the light comes on instantly. Here is what electricity actually is: free charge, a slow drift, and an energy wave racing along near light speed.

  2. 2

    Volts and Amps: Electrical Pressure and Flow, Explained

    Voltage is electrical pressure, current is flow, and multiplying them gives you watts. The two numbers on every appliance label, explained from first principles for Malaysian 230 V supply.

  3. 3

    What Is an Electric Circuit? Series vs Parallel

    Electricity only flows in a complete loop. What an electric circuit is, why your house is wired in parallel, and what actually happens in a short.

  4. 4

    Earthing and RCDs: Why Birds Don't Get Shocked

    A bird sits on a live line unharmed because there is almost no voltage difference across its body. That idea explains earthing, TT and TN-S, RCDs, and how to act near a fallen line.

  5. 5

    Power vs Energy: The Difference Between kW and kWh

    Power (kW) is how fast energy flows; energy (kWh) is how much flowed over time. Why the difference matters, and why your TNB bill charges for both.

AC and the machines

  1. 6

    AC vs DC: Why the Grid Alternates and Your Phone Does Not

    AC reverses direction 100 times a second so it can be transformed to high voltage and travel far; DC flows one way and runs the electronics inside every device. Here is why the grid picked one and your phone the other.

  2. 7

    How Generators Make Electricity: Spin Meets Wire

    Move a magnet past a coil of wire and current flows. That one trick, discovered by Faraday in 1831, is how every kilowatt-hour Malaysia burns gets made, and why the grid runs on a sine wave.

  3. 8

    How Transformers Work: The Grid's Quiet Machine

    The machine that made the national grid possible has no moving parts. How transformers work: two coils, one iron core, a changing field, and why it only runs on AC.

  4. 9

    Three-Phase Power Explained: Why Factories Get 400 V

    A house gets two wires; a factory gets four. Here is why three-phase power delivers constant torque, spins motors for free, and turns 230 V into a 400 V supply.

  5. 10

    How Electric Motors Work (and Run Everything)

    Around half the world's electricity ends up spinning a motor. How electric motors work: the squirrel-cage induction motor, slip, starting surge and the nameplate.

  6. 11

    kW, kVA and kVAR: The Power Triangle, Explained

    AC power comes in three flavours: real kW does the work, reactive kVAR builds magnetic fields, and apparent kVA is what the wires carry. Here is the power triangle, power factor, and why transformers are rated in kVA.

From the grid to your gadgets

  1. 12

    How the Malaysia Electricity Grid Reaches Your Plug

    Follow one kWh across the Malaysia electricity grid, from a Perak dam through 500 kV lines and substations to the 230 V at your socket. Then see why the tariff charges for peak demand and power factor, not just energy.

  2. 13

    Rectifiers and Inverters: Electricity's Translators

    The grid speaks AC; solar panels, batteries, LEDs and every chip speak DC. Rectifiers and inverters are the translators between them, and a modern building is quietly full of both. Here is how they work.

  3. 14

    How Batteries Store Energy (and Why It Is All DC)

    A battery does not store electricity; it stores chemical potential and manufactures current on demand. Why that is inherently DC, what the two datasheet ratings mean, and where storage pays off in a Malaysian building.

Finish

  1. 15

    Capstone: Read a Building's Electrical Story

    A worked exercise to finish the course. Trace the electricity from a power station to the office tower's pantry kettle, then work from a load list to kWh, from a motor nameplate to measured input, and from kW to kVA, and finish with a safety check.

Optional side readings

Background and history. Not needed to finish the course.