since several diodes may have to be replaced before the trouble is corrected. To determine
which stages failed and which diodes are not defective, all of the removed diodes must be
tested. You can do this by observing whether the equipment operates correctly as each of
the removed diodes is reinserted into the equipment.
1-104. The only valid check of a diode is a dynamic electrical test that determines the
diode's forward current (resistance) and reverse current (resistance) parameters. You can do
this test by using various crystal diode test sets that are readily available from many
1-105. Now that we have completed this chapter, the following is a short review of the
more important points. Answer the check-on-learning questions, found after the summary,
to determine how much you have learned from this chapter.
THE UNIVERSE - consists of two main parts (matter and energy).
MATTER - anything that occupies space and has weight. Rocks, water, and air are
examples of matter. Matter may be found in any one of three states: solid,
liquid, and gaseous. It can also be composed of either an element or a
combination of elements.
ELEMENT - a substance that cannot be reduced to a simpler form by chemical
means. Iron, gold, silver, copper, and oxygen are all good examples of
COMPOUND - a chemical combination of two or more elements. Water, table
salt, ethyl alcohol, and ammonia are all examples of compounds.
MOLECULE - the smallest part of a compound that has all the characteristics of
the compound. Each molecule contains some of the atoms of each of the
elements forming the compound.
ATOM - the smallest particles into which an element can be broken down and still
retain all its original properties. An atom is made up of electrons, protons, and
neutrons. The number and arrangement of these particles determine the kind of
23 June 2005