1-44
EL = 2
20
EL = 40 volts a.c.
ER = IT
R
ER = 2
5
ER = 10 volts a.c.
You can see that there is a voltage gain across the reactive components at resonance.
If the frequency was such that XL and X
C
were equal to 1000 ohms at the resonant frequency, the
reactance voltage across the inductor or capacitor would increase to 2000 volts a.c. with 10 volts a.c.
applied. Be aware that potentially high voltage can exist in series-resonant circuits.
SUMMARY
This chapter introduced you to the principles of tuned circuits. The following is a summary of the
major subjects of this chapter.
THE EFFECT OF FREQUENCY on an INDUCTOR is such that an increase in frequency will
cause an increase in inductive reactance. Remember that XL = 2
p
fL; therefore, XL varies directly with
frequency.
THE EFFECT OF FREQUENCY on a CAPACITOR is such that an increase in frequency will
cause a decrease in capacitive reactance. Remember that
therefore, the relationship between XC and frequency is that XC varies inversely with frequency.
