THE CARBON COMPOSITION RESISTOR.
By grinding carbon into a fine powder and mixing it
with resin, a material can be made with different
resistive values. Conductive leads are placed on
each end of a cylinder of this material and the unit is
then heated or cured in an oven. The body of the
resistor is then painted with an insulating paint to
prevent it from shorting it touched by another
component. The finished resistors are then
measured and sorted by value (Figure 4). ll these
resistors are overloaded by a circuit, their resistance
will permanently decrease. It is important that the
power rating of the carbon composition resistor is
not exceeded.