Potentiometer Wiring
A potentiometer can be wired in two main ways: voltage divider or variable resistor (rheostat). Understanding both is essential for correct circuit design.
Potentiometer Terminals
- Pin 1 → One end of resistive track
- Pin 2 → Wiper (middle terminal)
- Pin 3 → Other end of track
1. Voltage Divider Wiring (Most Common)
Used to control voltage level (e.g., volume control).
- Pin 1 → Vcc (input voltage)
- Pin 3 → Ground
- Pin 2 → Output (variable voltage)
As you rotate the knob:
- Output voltage changes from 0V → Vcc
Voltage Divider Principle
::contentReference[oaicite:0]{index=0}The output voltage depends on the resistance ratio between the two sections.
2. Variable Resistor (Rheostat)
Used to control current instead of voltage.
- Use only two pins:
- Pin 1 → Input
- Pin 2 → Output
- Pin 3 → Not connected
Resistance changes as knob is rotated.
Reversing Direction
If rotation direction is reversed:
- Swap Pin 1 and Pin 3
Common Applications
- Audio volume control
- LED brightness control
- Motor speed control (low power)
- Signal tuning
Example
12V supply with potentiometer:
- Pin 1 → 12V
- Pin 3 → Ground
- Pin 2 → Output varies 0–12V
Common Mistakes
- Connecting wrong pins
- Using as rheostat but leaving wiper floating
- Using low-power pot in high current circuit
Important Notes
- Voltage divider uses all 3 pins
- Rheostat uses 2 pins
- Always check pin orientation
- Use correct power rating