"Joel Kolstad" wrote in message
...
[...]

I started going through the math involved and determined that you can
readily
confuse yourself if you don't make the "high Q" assumption. For instance,
something like a 1 ohm source and 1 ohm load feeding a tank of 159.2mH (j1
ohms) and 2 318.3mF caps (-j/2 ohms) has such a horribly low Q that there
isn't a 180 degree phase shift top to bottom, nor is the resonant
frequency
1Hz.

Thanks,
---Joel Kolstad



Made an inductance meter based on a resonant LC circuit and used a PIC to
back calculate the inductance and Q values based on known F and C and
currents. Circuit was able to work down to Q values of 1 at frequencies
down to 5Hz. Worked well.
Did the programming and found it just wouldn't calculate the correct L
values when working at low Q. Spent hours doing tests until it dawned on me
that I'd stupidly programmed in the "standard" resonance formula.
Suddenly became sweetness and light when I reprogrammed for ...
Frequency= 1/2*pi * sqrt(1/LC -R^2/L^2).
I continue to live and learn
john



--
Posted via a free Usenet account from http://www.teranews.com