LC Tank question; 'Q' detector
Tapperman
Posts: 319
Has anyone written an object to read the 'Q' of an LC-Tank (parallel)?
I think I've found a way to do it, and I don't want to 're-invent-the-wheel', if it has already been written before.
Thanks for your attention and input ahead of time,
... Tim
I think I've found a way to do it, and I don't want to 're-invent-the-wheel', if it has already been written before.
Thanks for your attention and input ahead of time,
... Tim
Comments
Most of the stuff that I have done focuses on the peak value near the resonant frequency and since I mostly wind air-coils, they generally will have a higher Q than those with a core. To find the Q you would need to determine the energy levels under the envelope on either side of the resonant frequency. i.e. how much bandwidth your occupying under the target frequency.
1. Set the frequency to resonance.
2. Vary the resistor until the voltage across the parallel LC circuit is 1/2 the driving voltage.
3. The Q is calculated as R/(impedance of either the L or C)
I'm not sure this is completely rigorous but it's close.
Duane J
Well, I'm still testing some of this out. But I do have a document or two which help show the direction I'm headed. Since you have steered me in the right direction in the past, I thought your review of this material would be very helpfull. And I'm always looking for a little 'ego' stroking too!
Anyway, more on this later
... Tim
I think I'll use this to test my objects (how accurate are they) ... Thanks for the info
... Tim