ELECTRONIC PRINCIPLES - OD1647 - LESSON 1/TASK 2
The various types of modern military equipment are literally
loaded with semiconductor devices. Many radars, communication,
and much airborne equipment are transistorized. Data display
systems, data processing units, computers, and aircraft guidance
assemblies are all good examples of electronic equipment that
use semiconductor devices. All of the specific applications of
semiconductor devices would make a long and impressive list.
The fact is, semiconductors are now being used extensively in
commercial products, industry, and all branches of the armed
services.
b. Semiconductor Competition. Semiconductor devices perform
all the conventional functions of rectification, amplification,
oscillation, timing, switching, and sensing. Simply stated,
these devices perform the same basic functions of the electron
tube but perform more efficiently, economically, and for a
longer period of time. Therefore, these devices are used in
place of electron tubes, and it is natural and logical to
compare semiconductor devices with electron tubes.
Physically, semiconductor devices are much smaller than tubes.
As can be seen in figure 71 on the following page, the
difference is quite evident. This illustration shows some
commonly used tube sizes. alongside semiconductor devices of
similar capabilities. The reduction in size can be as great as
100: 1 by weight and 1000: 1 by volume. It is easy to see that
size reduction favors the semiconductor device. Therefore,
whenever miniaturization is required, or is convenient.,
transistors are favored over tubes. Bear in mind, however, that
the extent of prtactical size reduction is a big factor;
however, many things must he considered. Miniature electron
tubes, for example, may be preferred in certain applications to
transistors, thus keeping size reduction a competitive area.
Power is also a twosided story. For lowpower applications,
where frequency is a significant factor, semiconductors have a
decided advantage. This is true mainly because semiconductor
devices perform very well with an extremely small amount of
power; in addition, they require no filaments or heaters as in
the case of the electron tube. For example, a computer
operating with over 4000
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