NapkinCalc

Electricity 1 — DC Circuits

The voltage divider

continues from lesson 2 — values defined earlier in the course stay live here

ELI5: two resistors in series split the supply voltage in proportion to their sizes — the bigger resistor keeps the bigger share. It's the single most-used sub-circuit in all of electronics.

the divider circuit — V_out is the formula below
the divider circuit — V_out is the formula below
Vout=Vs⋅R3R2+R3V_{out} = \frac{V_{s} \cdot R_{3}}{R_{2} + R_{3}} = 8.25 V voltage across R₃

Real-world hook: voltage dividers are the volume knob on an amp, how a sensor (a resistor that changes with light, heat, or pressure) reports a reading, and how a circuit makes a reference voltage.