What is the main role of common adjustable resistors?
The nominal value of the adjustable resistor is that the standard can be adjusted to a large resistance resistance value. In theory, the resistance value of the adjustable resistor can be adjusted to any value within 0 and the nominal value, but because of the actual structure and design accuracy requirements, etc. The reason, only "basically" is adjusted within the allowable range to change the resistance.
The common adjustable resistor is mainly to change the resistance by changing the length of the electrical blocking circuit. For a resistance that is sensitive to temperature, the temperature can be changed by changing the temperature, which is called a thermistor; Sensitive resistors, by changing the light intensity to achieve the purpose of changing the resistance, this is called a photosensitive resistance; in addition to this, there is a pressure sensitive resistance, a gas sensitive resistance, and the like.
It can gradually change the current in the electrical appliance it in series, or gradually change the voltage of the electrical appliance therebetween, and can also function as a protective electrical appliance. In the experiment, it also plays a role in obtaining multiple sets of values. The variable resistor is significantly higher than the normal resistor due to structural and use. Variable resistors are typically used in small signal circuits, and large signal variable resistors are also used in small number of electron tube amplifiers.