Electronics 1 — Filters & Op-Amps
Decibels, RC filters with the rolloff plotted live, op-amp gain you can dial, and sizing an LED resistor.
Electricity 1 and 2 moved power. Electronics moves signals — tiny voltages that carry information — and the whole game is shaping them: amplify this, filter out that, protect the next thing. Three workhorse building blocks below.
- 01 Decibels — the language of gain ELI5: signal chains multiply gains stage after stage, but multiplying big numbers is annoying — so engineers switch to decibels, where multiplying becomes…
- 02 The RC low-pass filter ELI5: one resistor + one capacitor = the simplest useful circuit there is. Slow (low-frequency) signals pass through; fast (high-frequency) ones get shorted to…
- 03 The op-amp — gain you choose with two resistors ELI5: an op-amp has absurd raw gain (~100,000) and is useless on its own. Feedback tames it: the amp adjusts its output to keep its two inputs equal, and then…
- 04 Sizing a real part: the LED resistor ELI5: an LED has a fixed voltage drop (~2 V) and will burn out if you let too much current through, so it needs a series resistor. The resistor…
next course: AC Motors →