BASIC ELECTRONICS - OD1633 - LESSON 1/TASK 2
FIGURE 35.
USE OF GROUND SYMBOLS.
ground is shown connected to point A.
Point C is 75 volts positive in
respect to ground.
In most electrical equipment, the metal chassis is the common ground for the
many electrical circuits. When each electrical circuit is completed, common
points of a circuit at zero potential are connected directly to the metal
chassis, thereby eliminating a large amount of connecting wire.
The
electrons pass through the metal chassis (a conductor) to reach other points
of the circuit. An example of a chassis grounded circuit is illustrated in
figure 36 on the following page.
Most voltage measurements used to check proper circuit operation in
electrical equipment are taken in respect to ground.
One meter lead is
attached to a grounded point and the other meter lead is moved to various
test points.
b. Open Circuit. A circuit is said to be open when a break exists in a
complete conducting pathway. Although an open occurs when a switch is used
to deenergize a circuit, an open may also develop accidentally. To restore
a circuit to proper operation, the open must be located, its cause
determined, and repairs made.
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