To decrease the resonant frequency of any tuned circuit, increase the inductance and/or increase the capacitance.
Resonance
A signal from a radio station is tuned in a radio receiver by applying the signal to a resonant tuned circuit that accepts the wanted signal while rejecting all the other signals arriving.
A particular radio station is selected on our radio set by adjusting the natural frequency of LC-circuitequal to the frequency of particular transmitting station.
if its an LCR circuit then Q=wL/R where W=angular frequency L=Inductance of the coil R=resistance of the coil
AFC was used to provide an electronic means to stabilize the frequency of a circuit. Older receivers and transmitters used a tank circuit, made of an inductor and capacitor to select frequency. Since both the inductor and capacitor are physical objects, their sizes and properties vary with temperature, humidity, age and other factors. Also to be able to tune the frequency, at least one of them had to be deliberately made to be mechanically alterable to change it's electrical properties. These factors caused the frequency to slowly drift over time. Also, the tuning was usually accomplished in a continuously variable way, so it was difficult to confirm an exact tuning to the station which could lead to loss of sensitivity or distortion of the signal. AFC used electronic feedback to fine tune the tank circuit by a (usually) electrically tuned component. Modern radio equipment tends to use a quartz crystal oscillator of a fixed frequency as a reference. Quartz crystals can easily be made stable in frequency to 50 parts per million. This is sufficiently accurate to not need to compare it with the frequency of the incoming signal, itself derived from a stable crystal source. The radio is usually tuned by a frequency synthesizer controlled by the crystal. Both AFC and the frequency synthesizer method use an electrically tuned variable frequency oscillator to tune the radio. The difference is that AFC used characteristics of the received signal to measure and correct the mistuning, while frequency synthesizers compare the tuning with crystal reference. AFC cannot find the frequency you desire to tune, it only fine tunes it once you select it. The frequency synthesizer accurately tunes the radio to whatever frequency you ask it.
what is resonant frequency
A parallel resonant circuit has low impedance, when non resonant; however the impedance rises sharply, as the circuit comes to resonance.
As a parallel resonance circuit only functions on resonant frequency, this type of circuit is also known as an Rejecter Circuit because at resonance, the impedance of the circuit is at its maximum thereby suppressing or rejecting the current whose frequency is equal to its resonant frequency.
No, the resonant frequency of a RLC series circuit is only dependant on L and C. R will be the impedance of the circuit at resonance.
Resonant in electronics circuit refer to tuning if the resonant condition arise it means the frequency where does the resonant arise is resonant frequency and the gain is highest on that particular frequency. it is widely used in receiver circuits.
For to keep the resonant frequancy constant L*C has to stay same. Lets say if you double L you have to divide C by 2 to keep the same resonant frequency. If only L increases Resonant frequency decrease, this is same for C.
Series resonance occurs when a circuit's inductive reactance is equal to its capacitive reactance. The resistance of the circuit is irrelevant.WebRep currentVote noRating noWeight
XL=Xc is the resonance condition for an RLC circuit
This is a very broad generalization, but in general, increasing the value of one or more capacitors in an electronic circuit will decrease the resonant frequency of one or more sections of the circuit.
A resonator is a circuit that responds to a narrow range of frequencies. A typical resonator is a tuned circuit containing an inductor and a capacitor in series or parallel. A series connected tuned circuit has zero impedance at the resonant frequency, while a parallel tuned circuit has infinite impedance at the resonant frequency. The resonant frequency in both cases depends on the inductance times the capacitance: F = 1 / (2.pi.sqrt(LC)) If the inductance is in Henrys and the capacitance in Farads, the answer is in Hz.
At resonant frequency, current in the circuit is maximum.Impedence is minimum.
Because the series resonant circuit has the lowest possible impedance at resonance frequency, thus allowing the AC current to circulate through it. At resonance frequency, XC=XL and XL-XC = 0. Therefore, the only electrical characteristic left in the circuit to oppose current is the internal resistance of the two components. Hence, at resonance frequency, Z = R. Note: This effect is probably better seen with vectors. Clarification: Resonant circuits come in two flavors, series and parallel. Series resonant circuits do have an impedance equal to zero at the resonant frequency. This characteristic makes series resonant circuits especially well suited to be used as basic pass-band filters (acceptors). However, parallel circuits present their maximum impedance at the resonant frequency, which makes them ideal for tuning purposes.