L.1.8 Differentiating EMC ferrite ↔ inductor The terminology used in this handbook clearly distinguishes between inductors and EMC ferrites in regard to the quality of the inductor: EMC ferrites are based on Ni-Zn materials. This material has good quality factors (Q < 3) above approx. 20 MHz – i.e. trimmed for high losses. These originate in the core material and serve to absorb EMC...
C2.0 ELECTROSTATIC NON-POLARIZED CAPACITORS C2.1 CONSTRUCTIONAL SOLUTIONS The search for capacitance in small volumes has created a number of different solutions, each with its advantages and drawbacks. We shall try in this chapter to describe both methods and problems of achieving large C/V ratios. Further details may be added in specific material sections. The latter part of this chapter deals with some general construction...
R 2 WIREWOUND RESISTORS R 2.1 GENERAL COMMENTS As the name indicates wirewound resistors consist of a resistive wire wound on a bobbin and supplied with a protective coating. Since the resistance wire never can serve as a termination wire because of solderability requirements, it has to be connected to the terminal leads or the like, usually by welding or brazing. The higher the...
R 1.9 NOISE R 1.9.1 Definition Noise manifests itself as a spontaneously fluctuating voltage whose instantaneous amplitude is randomly distributed. The instantaneous value is both unpredictable and of minor interest except in certain critical applications. Instead, one measures a time-averaged value. It consists of the root of the mean-square value of voltage transmitted in a particular frequency pass band. The noise consists of two...
R 1.11 VOLTAGE DEPENDENCE If we apply a voltage on a resistor, it’s resistance will drop slightly in certain types. Therefore, the resistance change is negative. The change per volt of applied voltage is called voltage coefficient, VC, and is expressed in %/V or better, μV/V. The coefficient is determined not only by the resistive material but also by the dimensions, i.e., the electrical...
