Ohm's law without hand-waving
A practical guide to voltage, current, resistance, power, and the assumptions behind the most-used equation in electronics.
Technical knowledge / practical context
Clear engineering notes, grounded in real decisions.
Practical electronics tutorials that connect first principles with component selection, circuit behaviour, measurement, and design limits.
Published notes
A practical electronics learning path.
These notes move from first principles into components and then into small circuits that appear constantly in real design work.
Resistors: more than just Ohm's law
Resistance value, tolerance, power rating, pull-ups, pull-downs, current sensing, and the real decisions behind a simple part.
Choosing an LED resistor properly
How to choose current, resistor value, and power rating for LED indicator circuits without relying on habit or guesswork.
Diodes, rectifiers, and protection
Forward voltage, real ratings, rectifier ripple, reverse-polarity protection, flyback paths, Zener clamps, and TVS selection.
Capacitors: storage, filtering, and decoupling
How capacitors behave in power rails, timing, filters, and signal circuits, with practical notes on real-world limits.
RC circuits: timing, filters, and real behavior
Time constants, charge curves, cutoff frequency, loading, PWM smoothing, ADC settling, thresholds, and component tolerances.
Inductors without the mystery
Energy storage, saturation, DCR, switching regulators, EMI filtering, and what happens when coil current changes.
Series and parallel resistance
The practical rules behind equivalent resistance, voltage division, current sharing, power, tolerance, and debugging.
Voltage dividers and why they sometimes betray you
Divider maths, loading, ADC source impedance, wasted current, tolerance, and when a divider is the wrong tool.
Transistors as switches
Using BJTs and MOSFETs to control loads from logic pins, including base resistors, gates, flyback, and safe defaults.
Op-amps without the hand-waving
Feedback, buffers, amplifiers, input range, output swing, bandwidth, offset, and when a comparator is the better part.
Common op-amp configurations
Voltage followers, non-inverting and inverting amplifiers, active filters, current sensing, and when a comparator is the better tool.
Current coverage
A grounded route through electronics.
The published series moves from electrical fundamentals to components, small circuits, protection, timing, and analogue systems.
Voltage, current, and resistance
Ohm's law, resistor behaviour, series and parallel networks, power, tolerance, and loaded dividers.
Passive parts and timing
Capacitors, inductors, stored energy, reactance, RC curves, filters, and practical component limits.
Light, switching, and protection
LED current limiting, diodes, rectification, clamps, flyback paths, BJTs, and MOSFET switching.
Op-amps and feedback
Ideal behaviour, real limitations, followers, inverting and non-inverting gain, sums, and differences.
Article style
Clear explanations tied to practical work.
Lab Notes are written to connect first principles with the kind of design choices that appear on real benches, boards, tools, and games.
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Start from the concept
Explain the idea without assuming the reader already knows the vocabulary.
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Show the practical limits
Include tolerance, loading, heat, noise, timing, or other details that change real outcomes.
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Connect to tools
Point to calculators and formula helpers where a reader can try the numbers.
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Keep it useful
Prefer examples, checks, and judgement over filler or abstract definitions.
Try the numbers
Continue from explanation to calculation.
The tools below apply the same principles with adjustable values, engineering units, worked results, and practical checks.
Ohm and resistor calculations
Solve voltage, current, resistance, power, resistor networks, loaded dividers, and preferred values.
Open the benchRC timing and passive filters
Plot charge curves, calculate time constants, compare filter responses, and inspect cutoff behaviour.
Open timing toolsDiodes and transistor switches
Size LED resistors, estimate device losses, check drive requirements, and review thermal margins.
Open device toolsCustom formula solving
Enter an equation from a datasheet, choose the unknown, assign values, and inspect the rearranged result.
Open formula labQuestions
Ask a technical question or request a clearer explanation.
Send a circuit, formula, programming pattern, or game-system question that would benefit from a clear practical explanation.