A potentiometer is defined as a 3 terminal resistor having a rotating or sliding contact that makes up the adjustable voltage divider. If you are using only the two terminals present in it (one end and the wiper), then it behaves like a variable resistor or rheostat.
Potentiometer, a measuring instrument, is a voltage divider which is used to measure the electric potential difference. This electric component has got its name as a potentiometer because it is an implementation of the same principle.
Potentiometers are used mainly in controlling electrical devices like in audio equipment for controlling the volume. Potentiometers that are controlled by a mechanism can be utilized as position transducers, like, as used in a joystick. Potentiometers are used very often to control significant power (greater than watt) directly since the dissipated power in the potentiometer is comparable to the power present in the controlled load.
Nomenclature for Potentiometers
There is a vast amount of electronic equipment present in the industry. For the simplification of the people, each of them comes with its code and nomenclature. Let's have a look at the nomenclature as described for a potentiometer.
- Trimmer pot or Trimpot – A trimmer potentiometer is a potentiometer that is generally meant to be calibrated once or infrequently for the electrical signal to get tuned finely.
- Thumbwheel pot or Thumb pot – A rotating potentiometer (small) which can be calibrated infrequently with the help of small thumbwheel.
- Slider pot or Slide Pot – This kind of potentiometer is adjusted with the help of a wiper by shifting it right or left (or even up and down - It depends on the way of its installation), generally with the help of thumb or a finger.
Digital Potentiometer
A digital potentiometer, generally known as digipot, is an electronic equipment that copies all the functionality of analog potentiometers. Just like the analog potentiometer, the resistance present between the 2 terminals can be adjusted through digital input signals.
There are 2 main functional types of digital potentiometers.
- Non-Volatile – It uses a strong mechanism like that present in EEPROM or flash memory to retain their set position.
- Volatile – It loses its set position as soon as the power is removed from them. It is generally designed to initialize at the base position.
The use of digipot is much complex than that of a simple analog potentiometer. Not only that, but there are many noticeable limitations as well. Still, they are broadly utilized, regularly for factory calibration and adjustment of hardware, particularly where the constraints of mechanical potentiometers are dangerous.
Membrane Potentiometers
A membrane potentiometer is a potentiometer that takes the help of a conductive membrane that is distorted by a sliding element to contact a resistor voltage divider. Linearity lies between 0.5 percent to 5 percent as per the designs, materials, and processes used while manufacturing. The repeat accuracy generally lies in the range of 0.1mm to 1.0mm with an infinite resolution theoretically.
This was all we have regarding Potentiometers. Brands that manufacture them are Bourns, Honeywell, and Vishay. Make sure to go through them using the links as provided.
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