// LAB 12 · INTERACTIVE
Voltage divider calculator
Two resistors share the voltage: slide them and watch Vout — like 5 V down to 3.3 V for an ESP32 pin.
⚡ POWERING UP THE LAB…
// HOW IT WORKS
The idea in 30 seconds
- Vout = Vin × R2 ÷ (R1 + R2). Equal resistors = half the voltage.
- Bigger R2 (bottom) = more of the voltage at the output.
- Replace R2 with an LDR or thermistor and Vout follows the light or temperature — that is how sensors talk to analogRead.
- A divider is for signals, not power: a load on the output pulls the voltage down.
Watch the lessons
More labs
All labs →LAB · INTERACTIVEOhm's law playgroundSlide the voltage and resistance, watch the current and power change live.LAB · INTERACTIVECapacitor chargingCharge and discharge a capacitor through a resistor and watch the curve.LAB · INTERACTIVESeries vs parallelBuild a chain or a ladder of resistors and see the total change.