chapter  34
6 Pages

Resistance variation

This type of resistor is made from a mixture of carbon black resin binder and a refractory powder that is pressed into shape and heated in a kiln to form a solid rod of standard length and width. The resistive value is predetermined by the ratio of the mixture. Metal end connections are crimped onto the rod to act as connecting points for electrical circuitry. This type of resistor is small and mass-produced cheaply; it has limited accuracy and a low power rating. Carbon resistors are used in electronic equipment.