Electronic circuits and devices employ many types
of transformers to provide the necessary voltages for
proper circuit operation, interstage coupling, signal
amplification, and so forth. The physical construction
of these transformers differs widely.
Power-supply transformers, used in electronic
circuits, are single-phase, constant-potential trans-
formers with either one or more secondary windings, or
a single secondary with several tap connections. These
transformers have a low volt-ampere capacity and are
less efficient than large constant-potential power
transformers.
Most power-supply transformers for
electronic equipment are designed to operate at a
frequency of 50 to 60 Hz. Aircraft power-supply
transformers are designed for a frequency of 400 Hz.
The higher frequencies permit a saving in size and
weight of transformers and associated equipment.
The typical transformer has two windings insulated
electrically from each other. These windings are wound
Table 3-1.-Principle Parts of a Transformer
on a common magnetic core made of laminated sheet
steel. The principal parts of a transformer and their
functions are given in table 3-1.
Figure 3-15.-Types of transformer construction: A. Core type; B. Shell type.
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