TABLE OF CONTENTS In the preceding chapters we saw that there is no such thing as a "pure resistor" and that secondary effects arising from the specific mechanisms of conduction or the geometry of resistive components are responsible for deviations or changes in the actual behavior of a resistor from Ohm's law. In the current chapter we will examine and determine the limits of this behavior.
[1]Significant portions of this chapter have been taken in their entirely from internal papers prepared by Mr. Cherbuy. a research engineer with the Vishay Sfernice Corporation, as well as from application notes on the characteristics of type S-102 resistors, prepared by the Vishay-Foil division.
For a resistor to be used or even measured, it must be connected to the remainder of the circuit or measuring device by means of conductors, which, like the resistor itself, introduce a non-zero ohmic value and self-inductance that must be taken into account if the current varies with time. In the same manner the dielectric medium that protects and insulates the resistor from external effects is characterized by very high, but not infinite, resistance and capacitance that influence the signal.
A resistor placed between the nodes of a network (Fig. 1) can be represented (in DC) by three local resistances: R, the nominal resistance; P, the insulating resistance between the input and output of the nominal resistance, and S, the resistance of the conductors (Fig. 2).
