Potentiometers are electrical components with variable resistance. Typically these components are used in conjunction with a knob; the user turns the knob, and the rotary movement is translated into a change of resistance in the electrical circuit. This resistance change is used to adjust some parameters of the electrical signal, such as the volume of the audio signal. Potentiometers are used in all types of electronic and mechanical components, large or small. Fortunately, with a little experience, learning how to connect a potentiometer is quite simple.
Steps
Step 1. Identify the 3 terminals on the potentiometer
Position the potentiometer so that the screw is facing the ceiling and the 3 terminals are facing you. With the potentiometer in this position, we will refer to the terminals as terminals 1, 2 and 3. Take note of these labels, as it is easy to confuse them when repositioning the potentiometer.
Step 2. Ground the first terminal
To use the potentiometer as a volume control (undoubtedly its most common use), terminal 1 must be connected to ground. To do this, you will need to solder an electrical wire to the terminal, and solder the other end of the wire to the chassis or frame of the electrical component on which you are going to install the potentiometer.
- Start by measuring the length of the wire you will need to connect to the terminal and find a convenient spot in the chassis to solder the wire. Use a pair of thread cutting pliers to cut the thread.
- Use a soldering iron to solder the first end of the cable to terminal 1. Solder the other end to the component chassis. In this way we will have grounded the potentiometer, allowing us to lower it to 0 by turning it completely.
Step 3. Connect the second terminal to the circuit output
Terminal 2 is the potentiometer input. This means that the output of the circuit must be connected to the input, or to the input, of the potentiometer. For example, on a guitar, this would be the lead coming out of the pickup. On an integrated amplifier, this would be the lead from the pre-amp stage. Weld as above.
Step 4. Connect the third terminal to the circuit input
Terminal 3 is the output, or the output, of the potentiometer, which means that it must be connected to the input of the circuit. On the guitar, this would mean connecting terminal 3 to the jack. On an integrated audio amplifier this would mean connecting terminal 3 to the speaker terminals. Carefully solder the wire to the terminal.
Step 5. Test the potentiometer to make sure it is connected correctly
Once the potentiometer is connected, you can test it with a voltmeter. Connect the leads of the voltmeter to the input and output terminals of the potentiometer and turn the screw. The value read on the potentiometer should change as you turn the knob.
Step 6. Place the potentiometer in the electrical component
Once the potentiometer has been connected and tested, you can install it as you see fit. Replace the electrical component cover and place a knob on the potentiometer if you need it.
Advice
- The instructions above analyze in detail the procedure for connecting a simple potentiometer for volume control, which is the area in which this type of electronic components are most used. Other uses require different potentiometers, which in turn require different wiring diagrams.
- For other uses that require only two wires, such as a handcrafted motor, you can create a kind of improvised variator by connecting the wires one outside and one inside.
