Resonance Simulation error . Beginner Finding!!!!

[lacy]

O.K. I would like to thank you Max. I think you have cleared up the error in my thinking about the Q-factor.

In the beginning I was thinking about the high voltages seen on the coil and capacitor and I really didn't see the real problem which was the current through R1 and the voltage drop not being as it should be in the math and I apologize for this error to the original poster of this thread. He was right and I was wrong. This probably won't be the last time I am wrong, either.

Thanks to every for an very productive discussion. I think everyone here learned something. I know I did.

One last thing Max, If we need to design a High Q circuit what would your recommendation be for simulator settings if we want to use the transient (flipping the run switch) simulation method?

[belfastsimon]

I have a similar issue reguarding the use of multisim and it's results compared to the theoretical values returned from the equations for resonance.

Useing a series RLC circuit connected to a variable freq AC supply, I want to find the frequency of resonance for the circuit by finding the peak of current and the point where the voltage drop over the capacitor equals the volt drop over the inductor.

Resistor = 100 Ohm

Capacitor = 8 nF

Inductor = 8 mH

AC supply = 10 V - frequency varies

the frequency I have found using the multisim simulation differs from the theoretical by over 200Hz (19638Hz for multisim; 19894Hz for the Theoretical)

Is the step timing of the multisim circuit simulation the reason why the resonant frequency varies so much or is this just a usual outcome from SPICE simulators?

Thank you in advance

Simon

[lacy]

Not to sound like a butthole or anything, but if you have read this entire thread then the answer to your questions is contained within it.

I will not go back through a reiterate what already has been discovered concerning this, but I would be safe in saying your assumptions are correct.