Potentiometers – adjustable resistors for many applications
Variable resistance devices are often used to control electrical and electronic devices. Such subassemblies allow the conversion of rotary or reciprocating motion and the change of resistance in the range from zero to 100% of the nominal resistance of this element. If you use the potentiometer as a voltage divider, using all three pins, then - after connecting a constant voltage and ground to the extreme pins - a voltage proportional to the position of the potentiometer slider will be present on the middle lead of the potentiometer.
In addition to the three terminals - pins - the potentiometer has a resistance path, a slide and an insulator. Modern potentiometers are very small due to the global minimalistic tendency, but it is possible to find out some bigger ones.
Construction of potentiometers – details
As we said, each potentiometer consists of a resistive element and a sliding contact that moves along that element. In addition, this element has a mechanical system that moves the middle contact. Many potentiometers are constructed with an arc-shaped resistor, usually slightly less than a full turn, and a contact that travels over the resistor during rotation to create electrical contact. In panel potentiometers, the slider is usually the middle terminal of the three pins. The situation is completely different in the case of single-turn potentiometers. In such devices, the contact may make one revolution about the axis (often incomplete). In the case of multi-turn potentiometers, mechanical elements are added to move the contact. Of course, the type of movement that the potentiometer makes is directly determined by the specificity of the resistor. Much depends on the type of device. In the described slide potentiometers, the voltage changes with a sliding movement on the vertical or horizontal axis. In the case of a rotary potentiometer - as the suggest - the rotary movement is done by turning the potentiometer knob.
How to choose a potentiometer?
The main parameter characterizing the potentiometer is the maximum nominal resistance. The second important parameter is resistance changes. Important concepts related to potentiometers include linear characteristic and logarithmic characteristic. When choosing a potentiometer, also pay attention to the permissible power. The choice of device largely depends on its application. Different potentiometers may fit the audio system, different car.
Of course, we wouldn't be ourselves if we didn't mention that the potentiometers will be useful for your DIY! If you are doing a DIY project, constructing your own robot or creating some home temperature control systems and other projects, then such potentiometers can be useful to you! You can use the products presented here for many various projects! If you have any questions, please don't hesitate to contact us!