RLC 電路
 
RLC 電路可以看成一個二階的微分方程式，其解必定含有 sin, con 函數
 
sin, con, 的值，隨著時間變動，經過一段時間後，會重複，所以是 一種重複性的函數，就像水波一樣
 
既然 像波一樣，就有頻率及振幅的問題。
 
振幅很容易可以計算出來，但頻率就比較難求，必須解出 微分方程式才能解出來。因此 RLC 電路的關鍵問題是求頻率。
 
RLC Circuit
v the voltage of the power source (measured in volts V)
i the current in the circuit (measured in amperes A)
R the resistance of the resistor (measured in ohms = V/A);
L the inductance of the inductor (measured in henrys = H = V·s/A)
C the capacitance of the capacitor (measured in farads = F = C/V = A·s/V)
q the charge across the capacitor (measured in coulombs C)
串聯 RLC 電路
V R + V L + V C = V


q is the charge across the capacitor

併聯 RLC 電路
I R + I L + I C = I


F is magnatic flux in the system