Variable Resistor is a resistor whose value prisoners can be adjusted as needed. Variable resistors change resistance between the center terminal and the terminal end of the shaft when rotated. Resistance value between terminals listed at the end of his body. In practice Variable Resistors can be distinguished:

-Variable linear resistors.
-Variable Resistor logarithmically.

The definition of linear variable resistors are variable resistors that change value detainees linearly proportional to the magnitude of turning angle. For this type of variable linear resistors are generally marked with a large letter B. While that is a logarithmic Variable Resistor Variable Resistor is a change in the value of the square of prisoners compared with the change of angle of rotation. This type of variable resistor is generally marked with a capital letter A. In a series of variable resistors are usually written with the letters VR mark.

This paper will use Variable Resistors manifold because prisoners can be arranged logarithmically slowly so it does not happen instantaneously stepping voltage.