1-43
Figure 1-24C.—Formation of a
p
-type filter.
SAFETY PRECAUTIONS
When working with resonant circuits, or electrical circuits, you must be aware of the potentially high
voltages. Look at figure 1-25. With the series circuit at resonance, the total impedance of the circuit is 5
ohms.
Figure 1-25.—Series RLC circuit at resonance.
Remember, the impedance of a series-RLC circuit at resonance depends on the resistive element. At
resonance, the impedance (Z) equals the resistance (R). Resistance is minimum and current is maximum.
Therefore, the current at resonance is:
The voltage drops around the circuit with 2 amperes of current flow are:
EC = IT
X
C
EC = 2
20
EC = 40 volts a.c.
EL = IT
X
L
