Direct current

Abstract

In this chapter we deal with the problem of determining the electric fields in conducting domains under the assumption that sources, i.e., charges and currents do not depend on time but, unlike electrostatics, currents are not null. In this case, the electric and magnetic fields are not coupled. Thus, we can compute first the current density which can be used later in the magnetostatic problem (Chap. 9) to obtain the magnetic fields. We will state the direct current problem in terms of the scalar electric potential and introduce the resistance and conductance matrices. At the end of the chapter we give a brief description of lumped direct current circuits.