Instructions for Professor Coyle: Professor Coyle is intended to be a mathematical aid in determining the inductance of a coil and the resonant frequency of a coil-capacitor tuned circuit. Spiderweb
calculator: The original Spiderweb calculator was
designed by Charlie
Cotterman and artwork added by Dan Petersen. To use the calculator,
enter the
required information in the indicated area in the red number area. The
calculator will give you the results indicated by the blue text in the
results
column. Looking at the representation of the spiderweb form, you will
note that
the dimensions you need are in the dimension lines. Enter the known inductance and capacitance into the calculator section at the top of the page. The resonant frequency and the reactance of the L-C circuit will be given in blue immediately below. Example: You have a 40-400pF variable capacitor and a 240uH inductor and you want to find the tuning range. Enter the inductor value, press <enter>, and the highest variable capacitor value into the calculator and press <enter>. You should see a resonance of .514 MHz. Left-click on the capacitance value and now enter 40. You should now see a resonance of 1.624 MHz. In this example would be perfect for tuning the AM broadcast band.The result is a theoretical value. The actual frequency will differ slightly due to distributed capacitance and measurement tolerances. |