1-25
acts to reduce or eliminate grid current;
acts to reduce plate current from what it would be if no bias existed;
is produced in other ways than just by a battery; and
is important for reasons other than those just studied.
OPERATION OF THE TRIODE
The circuit in figure 1-19 brings together all of the essential components of a triode amplifier. Before
analyzing the circuit, however, we need to define the term QUIESCENT.
Figure 1-19.—Triode operation.
The term quiescent identifies the condition of a circuit with NO INPUT SIGNAL applied. With a
given tube, bias supply, and plate supply, an exact amount of plate current will flow with no signal on the
grid. This amount is known as the quiescent value of plate current. The quiescent value of plate voltage is
the voltage between cathode and plate when quiescent current flows.
