Potentiometers & Variable Resistors

Potentiometers, often referred to as pots, are electronic components that are used to adjust voltage or current in a circuit. They are variable resistors that consist of a resistive element and a sliding or rotating contact, known as a wiper, which moves along the resistive element to change the resistance value.

Definition:
A potentiometer is a three-terminal device where the wiper's position determines the output voltage or current relative to the input. It operates on the principle of voltage division, where the wiper divides the total voltage across the potentiometer into two parts.

Function:
1. Adjustment: Potentiometers are used to adjust the level of a signal, such as volume control in audio systems.
2. Trimming: They are used to calibrate circuits by fine-tuning the resistance to achieve a desired output.
3. Tapping: Some potentiometers have multiple taps, allowing for multiple output voltages to be taken from a single device.

Applications:
1. Audio Equipment: For volume control and tone adjustment in amplifiers, speakers, and other audio devices.
2. Instrumentation: In measuring instruments for calibration and adjustment of input signals.
3. Motor Control: To control the speed of DC motors by adjusting the voltage across the motor.
4. Computer Peripherals: For adjusting the brightness and contrast in monitors and other display devices.
5. Automotive: For adjusting the idle speed in engines and other vehicle systems.

Selection Criteria:
1. Resistance Value: Choose a potentiometer with the appropriate resistance value for the circuit's requirements.
2. Power Rating: Ensure the potentiometer can handle the power dissipation expected in the application.
3. Linearity: For applications requiring precise control, a potentiometer with a linear taper (equal resistance change per rotation) is preferred.
4. Physical Size: Select a potentiometer that fits the available space in the device.
5. Environmental Conditions: Consider the operating temperature, humidity, and any potential exposure to dust or chemicals.
6. Resolution: For applications requiring fine control, a potentiometer with a high number of steps or a high resolution is necessary.
7. Type of Movement: Choose between rotary, linear, or slide types based on the application's mechanical design.

In summary, potentiometers are versatile components used in a wide range of electronic devices for adjusting and calibrating signals. When selecting a potentiometer, it is important to consider the specific requirements of the application, including resistance value, power rating, linearity, physical size, and environmental conditions.
Please refer to the product rule book for details.