← Back to Lab
Circuit Demos
The site builds the circuit — you watch and learn. Each demo walks you through a real circuit step by step with live explanations.
Beginner
LED Series Circuit
Your first circuit — understand current, voltage, and light
LEDResistorBattery
4 stepsWatch demo →
Beginner
Voltage Divider
Two resistors split voltage proportionally — key to sensor interfacing
ResistorVoltageOhm's Law
4 stepsWatch demo →
Beginner
Button Switch
Open and closed circuits — how switches control current
ButtonLEDSwitch
4 stepsWatch demo →
Intermediate
Transistor Switch
Control high power with a tiny signal — the heart of all electronics
TransistorNPNAmplifier
4 stepsWatch demo →
Beginner
Variable Brightness (POT)
Potentiometer as variable resistor — analog control
PotentiometerLEDAnalog
4 stepsWatch demo →
🎓
How do demos work?
Each demo shows a schematic circuit diagram with components highlighted as you progress. You can step through manually or hit the play button to auto-advance every 5 seconds. Current flow is animated so you can visually trace electrons through the circuit.