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Voltage divider

DC circuits · Beginner · about 10 minutes · part of Zen’s Electronics Design Mastery

Two resistors in series tap off a fraction of the supply. Vout = Vs · R2 / (R1 + R2), but only while nothing heavy loads the output.

Voltage divider: the circuit on the simulator's bench

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How it works

No load: Vout = Vs · R2 / (R1 + R2) = 3.837 V

With RL switched in, RL sits in parallel with R2 (2.35 kΩ), so Vout sags to 2.283 V. Keep RL ≫ R2 if the output must hold.

Try it on the bench

  1. Flip the load switch. The output drops because R_L steals current from R2.
  2. Set R_L to 100 kΩ, then flip the switch again. A light load barely moves the output.

Parts on the bench

In the course

Zen’s Electronics Design Mastery, module “DC Fundamentals”.

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