By hvhipot 
1. Application scope of series resonance
(1) The understanding method of impedance characteristics during resonance and the analysis of the working principle of LC series resonant circuit need to be divided into three frequency points and bands, namely resonance, input signal frequency higher than the resonance frequency, and input signal frequency lower than the resonance frequency.
When the input signal frequency is equal to the resonant frequency, the circuit resonates, and the impedance of the LC series resonant circuit is in the minimum state, which can be equivalent to a pure resistor. At this time, the signal current flowing through the entire resonant circuit is at its maximum. In circuit analysis, this is the most important point.
(2) The understanding method of impedance characteristics when the circuit is detuned: When the input signal frequency is higher or lower than the resonant frequency, the LC series circuit is in a detuned state, and the circuit impedance is larger than that when it is in resonance.
(3) Tuning of series resonance test system
By adjusting the air gap of the reactor core, the inductance of the reactor is continuously changed from the maximum value when the core is completely closed to the minimum value when the core is completely open (usually, the reactor can be tuned within the range of 4% to 90% of the core air gap). When the inductance of the reactor is equal to the circuit capacitance, the system reaches resonance. at this time
ωL=1/ωC
In the formula: L is the inductance of the reactor; C is the load capacitor; ω is the angular frequency (ω=2 π f, f is the input power frequency).
HV Hipot Electric Co., Ltd. specializes in the production of series resonance (also known as series resonance test withstand voltage device) and has been engaged in the electrical measurement industry for many years. Its products have first-class quality and welcome customers to come and purchase.