Wire a Potentiometer
Potentiometers, more commonly known simply as "pots," are a type of electrical component called a variable resistor. They usually function in conjunction with a knob; the user turns the knob, and this rotational motion is translated into a change in resistance in the electrical circuit. This change in resistance is then used to adjust some aspect of the electrical signal, such as the volume of an audio signal. Pots are employed in all manner of consumer electronics, as well as larger mechanical and electrical equipment. Fortunately, if you have a bit of experience working with electrical components, learning how to wire a potentiometer is a straightforward process.
Steps
- Identify the 3 terminals on the pot. Position the pot so that the shaft is facing up towards the ceiling and the 3 terminals are facing towards you. With the pot in this position, you can refer to the terminals from left to right as 1, 2, and 3. Make a note of these labels, as it can be easy to lose track of them when repositioning your pot while working.
- Ground the first terminal of the pot. For use as a volume control (by far the most common application), terminal 1 will provide the grounding. To do this, you will need to solder one end of a length of wire to the terminal, and solder the other end to the chassis or frame of the electrical component.
- Begin by measuring the length of wire you will need to connect the terminal to a convenient location on the chassis. Use a pair of wire snips to cut the wire to length.
- Use a soldering iron to solder the first end of the wire to terminal 1. Solder the other end to the component's chassis. This will ground the pot, allowing it to be turned all the way to zero when the shaft is at the minimum position.
- Wire the second terminal to the circuit's output. Terminal 2 is the input of the potentiometer, meaning the output line from the circuit should connect to it. For example, on a guitar, this would be the wire leading away from the pickup. In an integrated amplifier, this would be the wire leading from the pre-amp stage. Solder this connection as before.
- Wire the third terminal to the circuit's input. Terminal 3 is the output of the pot, which means it should be wired to the circuit's input. On a guitar, this would mean wiring terminal 3 to the output jack. On an integrated audio amp, this would mean wiring terminal 3 to the speaker terminals. Solder the wire carefully to the terminal.
- Test the pot to make sure it's wired correctly. Once the pot is wired, you can test it using a voltmeter. Connect the voltmeter's leads to the input and output terminals of the pot and turn the shaft. The reading on the voltmeter should change as the shaft is turned.
- Position the potentiometer inside the electrical component. Once the pot is wired and has been tested, you can position it as needed. Replace the cover of the electrical component and place a knob over the shaft of the pot if desired.
Tips
- The instructions above detail the process for wiring a pot as a simple volume control, the most common application. Many other tasks can be performed by potentiometers which require different wiring schemes.
- For other purposes involving only 2 wires, such as with a hobby motor, you can make a makeshift sort of dimmer switch by hooking the wires one on the outside and one on the inside.
Warnings
- Make sure to unplug all electrical components before working on them.
Things You'll Need
- Potentiometer
- Wire
- Wire snips
- Soldering iron
- Resin core solder
- Voltmeter
- Knob
