Mobile menu
5 1 1 1 1 1 Rating 5.00 (1 Vote)

LC circuit calculation

LCR circuitIn "LC circuit" sheet the Coil32 computes the values of capacitance, inductance, and frequency for a resonance oscillating circuit. The calculation is made by the Thomson's formula, derived in 1853, and which is all we know of the school course of physics:

 where:The Thomson's formula

  • f - frequency (Hz);
  • L - inductance (H);
  • C - capacitance (F);


The program allows you to calculate:

  • The resonant frequency of the LC-circuit at a known capacitance and inductanceLord Kelvin
  • The LC-tank capacitance at a known resonant frequency and inductance
  • The inductance of an LC-circuit for a known capacitance and the resonant frequency

Such a calculation is also implemented in the online calculator of the LC-circuit.

In the "Coil" sheet for single-layer coils, the program generates additional results for parallel LC-circuit:

  • The capacitance at the resonant frequency.
  • The characteristic impedance of the circuit:characteristic impedance formula
  • The equivalent resistance of the circuit:equivalent resistance of LC-circuit

By default, these calculations are not displayed. To enable output additional calculations in the output text box you need to click the corresponding button in the toolbar above it.

Calculations are correct of course for an unloaded circuit.
Q-factor contour of the capacitor is not taken into account.
The self-capacitance of the coil is not taken into account, so these calculations are meaningful at frequencies much smaller than the self-resonance frequency of the coil.


Latest comments