MAGNETIC CIRCUITS
Basic Electrical Theory
Summary
The important information contained in this chapter is summarized below.
Magnetic Circuits Summary
Simple magnetic circuit magnetic flux (F) is proportional to the
magnetomotive force (Fm) and indirectly proportional to the reluctance (R)
in a circuit.
F (Wb)
Fm (At)
R
At
Wb
A BH magnetization curve shows how much magnetic flux density (B)
results from increasing magnetic flux intensity. The "knee" identifies the
point where increasing flux intensity (H) results in a minimal increase in
flux density (B).
Hysteresis losses are caused by reversing current direction thousands of
times in a coil.
Faraday’s Law of Induced Voltage depends on the number of turns of a coil
and how fast the conductor cuts across the magnetic lines of force or flux.
Vind
NDF
Dt
Lenz’s Law states that an induced voltage will have a polarity that will
oppose the magnetic field that caused the induced voltage.
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