Construction base resistor can be set consists of a track made of a resistive material and a tracer (wiper) moveable such that it makes contact with the resistive path. The simplest construction as shown in Figure 1.12. This method of manufacture of this resistor can be grouped into three main groups, which are distinguished by a resistive material used:
a. Carbon, can be printed with a composition of carbon in the form of solid lines, or a carbon layer plus filler whose function is to isolate lapisam bottom (substrate).
b. Winding wire, nichrome or other resistance wire that dlilit on forming material accordingly.
c. Cermet, a thick film resistance layer in the form of lower layers of ceramic.
Several different types of resistor 78ariable have been produced, such as from a single coil type shear to form open or closed, until that has lots of loops (multi-turn). Components of this type has a resistance value is set to be smooth continuously along the entire path, and therefore a mechanical potentiometer on the application should be strong, stable and can be used to perform a repetitive before failure.
In general, the need for a potentiometer is included in one of the following categories:
a. Used for the initial setup (preset) or trimer
b. Regulator for general purposes, such as regulating the tone of voice
c. Precision regulator.
Figure 3.9. Construction variable resistor