Learn the top ten threats that are present in modern web-application development and how to protect your business from them.

The instructions are the following.

Connect a function generator (squarewave!!),

large inductor and small capacitor in series, with the cap. grounded.

Watch cap. voltage on o'scope-> exponentially-decaying sinewave.

Measure half life (thl) to find time constant (tau=thl/ln2). Measure

oscillation period (Td) to find damped resonant frequency (Wd) Ask

question: Does 1/tau^2 + w(omega)d^2=1/(LC)??

Is there some way to get the half life time and oscillation period of this circuit if

I know the values of the RLC? I need to compare the experiments with some real

results just to make sure I did this correctly? Also the R here is from the function generator

Connect a function generator (squarewave!!),

large inductor and small capacitor in series, with the cap. grounded.

Watch cap. voltage on o'scope-> exponentially-decaying sinewave.

Measure half life (thl) to find time constant (tau=thl/ln2). Measure

oscillation period (Td) to find damped resonant frequency (Wd) Ask

question: Does 1/tau^2 + w(omega)d^2=1/(LC)??

Is there some way to get the half life time and oscillation period of this circuit if

I know the values of the RLC? I need to compare the experiments with some real

results just to make sure I did this correctly? Also the R here is from the function generator

Experts Exchange Solution brought to you by

Enjoy your complimentary solution view.

Get every solution instantly with Premium.
Start your 7-day free trial.

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

reactance of L = 2 pi f L

reactance of C = 1/(2 pi f C)

you will have measured tau, you know L and C, the above info will allow you to calculate wd, so if tau checks out you will probably be doing things correctly.

---------------

f is not the sig gen frequency but it the frequency of the exponentially decaying sine wave as measured by the oscilloscope in the instructions.

Reactance is either capacitive or inductive except at the resonance frequency in which case the reactance is neither capacitive nor inductive, but just simple dc resistance; theoretically zero ohms at resonance with just an inductor and capacitor in the curcuit.

However in actuality, the resistance at resonance is at least slightly above zero ohms: It's the internal dc resistance of the wires, connectors and physical imperfections of the circuit components plus the effect of any actual resistor-like elements in the circuit.

(resonance in a circuit requires there to be both a capacitive (C) and a inductive (L) components)

The R is the internal resistance that is presented by the function generator when it is connected in the circuit. Being a (serial) component in the circuit and a real physical device (rather than a theoretical one) it presents some resistance of its own -- can't get around it.

It is used to calculate the resonate frequency of the circuit. (In your case the wd)

It is the ac equivalent of resistance. It is used in the ac ohms law. You cannot do ac circuits without it.

It is the frequency f at which the reactance of L and C have the same magnitude.

I assume that you know the values of L and C. and that you know what 2 and pi are. That leaves you to calculate the f.

But you said that you knew what the L an C were.

If you do not know what L and C are, there is no way you can calcaulat the resonated frequency.

"Measure half life (thl) to find time constant (tau=thl/ln2)"

----

You do not have to measure tau to calculate f

To get the resonant frequency - yes - see above

To get tau - not without more difficulty that you want to undertake. But that calculation is not important. If your oscilloscope shows something near to the frequency you calculated, you are doing something right. If you can see the oscillations decaying, you can be quite sure that your tau will be acceptable.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trialYou should certainly be able to solve for the natural frequencies.

http://www.lautsprechershop.de/tools/index_en.htm?/tools/t_schwingkreis_en.htm

Remember R is any restance you have in the series circuit including the internal restance of the generator.

Math / Science

From novice to tech pro — start learning today.

Experts Exchange Solution brought to you by

Enjoy your complimentary solution view.

Get every solution instantly with Premium.
Start your 7-day free trial.