Basic Electrical Theory
What is a magnetic circuit? To better understand magnetic circuits, a basic
understanding of the physical qualities of magnetic circuits will be necessary.
EXPLAIN the physical qualities of a simple magnetic circuit,
including relationships of qualities and units of measurements.
Given the physical qualities of a simple magnetic circuit,
CALCULATE the unknown values.
DESCRIBE the shape and components of a BH magnetization
EXPLAIN the cause of hysteresis losses.
Given Faradays Law of induced voltage:
DESCRIBE how varying parameters affect induced voltage.
CALCULATE voltage induced in a conductor moving through
a magnetic field.
STATE Lenzs Law of induction.
A magnetic circuit can be compared with an electric current in which EMF, or voltage, produces
a current flow. The ampere-turns (NI), or the magnetomotive force (Fm or mmf), will produce
a magnetic flux F (Figure 26). The mmf can be compared with EMF, and the flux (F) can be
compared to current. Equation (1-16) is the mathematical representation of magnetomotive force
derived using Ohms Law,
magnetic flux, Wb
magnetomotive force (mmf), At