As each area of technology with a potential for significantly impacting
any major segment of the electronics industry evolves, it often is
accompanied by the development of a succession of new circuits. Each new
circuit indeed appears different, employing different components in
differing configurations, and claims an assortment of distinct features
of "improved performance. " Without a considerable investment of
laboratory time to construct, evaluate, and compare each candidate
circuit, it usually is difficult to realistically appraise the relative
merits of one approach over another. It often is even more difficult to
identify the underlying principles which point up basic similarities and
differences. Such is the situation in the new and rapidly expanding area
known as electronic power processing or switching mode power supplies.
The area of switching power supplies has been spurred by the need for
power sources of higher performance, smaller volume, and lighter weight
in order to achieve compatibility with the shrinking size of all forms
of communication and data handling systems, and particularly with the
portable battery-operated equipment in everything from horne appliances
and handtools to mobile com- munication equipment. Static dc-to-dc
converters and dc-to-ac inverters provide a natural interface with the
new direct energy sources such as solar cells, fuel cells,
thermoelectric generators, and the like, and form the central ingredient
in most uninterruptable power sources.