Syntonic circuit is in the alternating current way that has L of resistor R, inductance and capacitance C element, circuit the voltage of two end and among them electric current it is different commonly. If we adjust circuit element (L or C) parameter or power source frequency, can make they a photograph is same, whole circuit appears for pure resistor sex. Circuit achieves what this kind of condition says to be resonance. Below syntonic condition, the total impedance of circuit reachs extreme value or reach extreme value approximately. The purpose that studies resonance should understand this kind of objective phenomenon namely, make full use of on science and applied technology syntonic feature, want to prevent the harm that it produces again at the same time. Those who press circuit connection is different, have series connection resonance and shunt-wound resonance two kinds.

 

When series connection is syntonic, inductance voltage and bugle call of surprise of capacitance voltage equivalence, namely electric electrification allows those who draw equivalence different number not to have result power, make circuit is absorbed it is without result power 0; Electric field energy and magnetic field energy are changing ceaselessly, but this adds those to decrease, mutual compensation, this part energy is between electric field and magnetic field oscillation, summation of energy of field of complete circuit electromagnetism is changeless; The resistor of energy complete translate into of incentive supply circuit is calorific. To maintain oscillation, drive must furnish ceaselessly what energy compensates resistor is calorific use up, compare every oscillation with the photograph of total electromagnetism field energy in circuit the energy that circuit wastes is less, the quality of circuit is better.

 

 

Of the communication experiment regulations as each local cable be built ceaselessly and power system high capacity tries tasted grow in quantity, power source of power source of series connection resonance applies in power system more and more extensive, the knowledge that asks we are syntonic to series connection is ceaseless and thorough, the application of our will syntonic to series connection principle and power source of series connection resonance in the spot and everybody spread out together discuss.

 

Say syntonic generation first, resonance is the circuit that has composition of component of R, L, C a kind of below certain condition special appearance, the condition that we guide everybody to analyse series circuit of R, L, C to produce resonance together first is harmonious brace up when the feature of circuit, if the graph is shown 1 times, series circuit of R, L, C falls in the action of sine voltage ∪ : Its answer impedance is:

 

 

 

In type, reactance X=X1-Xc is the function of horny frequency W, the circumstance that X changes along with W is shown 2 times like the graph, when W from 0 when beginning to change to ∞ , x from – ∞ to + ∞ changes, in W ” when W0, x ” 0 when, circuit is look sex, in W ” when W0, x ” 0 when, circuit is sensibility, when W=W0, right now, circuit impedance Z (W0) =R is pure resistor, voltage and electric current are inphase, we circuitry right now job status calls resonance, because this plants syntonic in RLC series circuit happening, we can call series connection resonance again, circuit of series connection resonance, formulary the 1 syntonic condition that is series circuit happening, can get W of syntonic horn frequency from this. Pursue as follows:

 

 

Syntonic frequency is

 

This shows, the syntonic frequency of series circuit is by L of circuit oneself parameter, c decides, have nothing to do with exterior condition, when power source is constant, can adjust L, c makes circuit natural frequency and power source frequency are consistent and produce resonance.