Learning module

Inductors

Inductors store energy in magnetic fields and resist changes in current.

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ElectroLab AI teaches theory, low-voltage electronics, and planning concepts. Mains voltage, switchboards, fixed wiring, high-current systems, and legal electrical work must only be performed by licensed electricians where required.

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Mark lessons as complete as you work through the bench checks, then use the quiz to test the ideas.

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Current lesson

Inductors

Start here

Load the electromagnet example in the simulator, close the switch, and compare current before and after changing coil resistance.

Key ideas

An inductor is usually a coil of wire that stores energy in a magnetic field.

Inductors resist sudden changes in current, which creates useful filtering and switching behaviour.

A coil with an iron core can become an electromagnet.

When coil current is interrupted, the collapsing magnetic field can produce a damaging voltage spike.

Useful formulas

RL time constant: tau = L / R

Inductor voltage: V = L x di/dt

Energy: E = 0.5 x L x I^2

Bench checks

Measure coil resistance before connecting a battery.

Estimate coil current with Ohm's Law.

Add a flyback diode across DC relay coils or electromagnets.

Common mistakes

Connecting a low-resistance coil straight across a battery for too long.

Forgetting flyback protection on switched coils.

Expecting inductance value alone to tell you the safe current rating.

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