Figure 15-2. Capacitor Action.
magnetic field. It does this because it soon becomes
moves first in one direction and then in the other. Each
charged and thereby opposes any further current flow.
time, the capacitor charges and discharges. And each
In a sense, it acts like a spring to bring the current to a
time the amount of current would be a little less, as some
of it is used up in heating the electromagnet. Shortly, the
alternations would stop. In actual operation, they end in
(5) If no other external action took place to
a fraction of a second.
change the conditions, the capacitor then discharges
c. Mutual Induction (Fig. 15-1).
back into the electromagnet. As it does, there would be
a magnetic buildup (opposed by a countervoltage),
followed by a magnetic collapse as the capacitor
(1) If a second winding were placed close to the
completes discharging (again opposed by a
first and connected to a lamp of the proper size, as
countervoltage). The result is a rapid swing of current
shown in figure 15-1, the effect of the magnetic buildup
back and forth as it