Learning module
Capacitors
Capacitors store charge, smooth supplies, pass changing signals, and block steady DC.
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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
Capacitors
AC vs DC
DC flows one way. AC changes direction repeatedly and is used for power distribution.
Resistors
Resistors limit current, divide voltage, set bias points, and turn electrical energy into heat.
Capacitors
Capacitors store charge, smooth supplies, pass changing signals, and block steady DC.
Inductors
Inductors store energy in magnetic fields and resist changes in current.
Transformers
Transformers transfer AC energy through magnetic coupling and change voltage by turns ratio.
Amplifiers
Amplifiers use a small signal to control a larger signal for audio, sensors, and communication.
Speakers
Speakers use a voice coil in a magnetic field to move air and create sound.
Radio Waves
Radio uses electromagnetic waves to carry information through space.
Solar Basics
Solar panels provide variable DC power that needs regulation before charging batteries.
Visual schematic
RC charge timer
The resistor controls how quickly the capacitor voltage rises. Bigger R or C means a slower timing action.
TP1: supply
TP2: capacitor voltage
TP3: trigger/output
Interactive lesson workbench
Move the controls and watch the idea change.
This is a simplified teaching model for Capacitors. Use it to build intuition before opening the calculator, lab, or real bench.
What changed?
A 100 uF capacitor through 10 k ohms has tau = 1.00 s. After one tau it is around 63% of 5 V.
Guided lesson coach
Work through Capacitors like a bench exercise.
First, name the job of the part or idea.
Say what it controls, stores, blocks, transfers, or protects. If you can explain that plainly, the formulas become much easier to use.
Start here
Build an RC delay with a resistor, capacitor, and LED indicator, then change the capacitor value and observe the timing shift.
Key ideas
A capacitor stores energy in an electric field between two plates.
Capacitors resist sudden voltage changes, which makes them useful for smoothing and timing.
Small capacitors often handle noise and signal coupling; larger electrolytics often handle storage and supply smoothing.
Electrolytic capacitors are usually polarised and can fail badly if connected backwards.
Useful formulas
Charge: Q = C x V
Energy: E = 0.5 x C x V^2
RC time constant: tau = R x C
About 5 tau is close to fully charged
Bench checks
Check voltage rating before installing a capacitor.
Confirm polarity on electrolytics before powering.
Use the RC calculator to predict charge or delay behaviour.
Common mistakes
Using too low a voltage rating.
Putting a polarised capacitor backwards.
Assuming a charged capacitor is safe just because power is off.