MANUFACTURING: Two processes are used manufacturing.

Coated film: A mixture of carbon, filler and binder is coated on a ring of insulating material. The surface of the film is processed to minimize abrasion of the film by the sliding contact tap. The contact is of brass or phosphor bronze. The contact is sparing loaded against element.

SPECIFICATIONS

Range of values                                                100 ohms to 10 mega ohm

Power rating                                                      1/2W to 2.5W

Tolerance                                                         20% for 100 ohms to 1 mega ohm

                                                                       30% above 1 mega ohm

Voltage coefficient                                             0.005% volt

APPLICATIONS: These are used as present potentiometer in TV, in brightness and contrast control, radio and measuring instruments.