variable resistors

what is a variable resistor? a resistor whose value you can twist/slide. a 3-terminal potentiometer makes a voltage divider; using just two terminals makes a rheostat (adjustable series R).

notes

• values: 1 kΩ–100 kΩ are common. choose so divider current is modest (e.g., 0.1–1 mA).
• taper: linear (B) for general use, audio/log (A) for volume knobs.