Khi may bat dk song co tan $w$ thi mach xay ra cong huong tuc la
$I_{1}=\frac{U}{R}$ va $Z_{L}=Z_{Co}$
Khi xoay tu thi
$I_{2}=\frac{U}{\sqrt{R^{2}+(Z_{L}-Z_{C1})^{2}}}=\frac{I_{1}}{n}=\frac{U}{nR}$
$=>n^{2}R^{2}=R^{2}+(Z_{Co}-Z_{C1})^{2}<=>Z_{C1}=Z_{Co}\pm \sqrt{n^{2}-1}.R$
$\frac{1}{wC_{1}}=\frac{1}{wCo}\pm \sqrt{n^{2}-1}.R$
$C_{1}=\frac{Co}{1\pm w\sqrt{n^{2}-1}.R}$