In Reply to: RE: -3db is 45 degrees phase shift, how much phase shift is -1db? (nt) posted by Tre' on January 29, 2015 at 19:46:03:
Hey,
Assuming a first order filter the -1dB point is an octave above the -3dB point so you can just use L = R/(pi*F) (or you could use 14hz and 2piFL).
The problem you are going to have is finding what value was used for R in the transformer test. A possibly better test would be to apply an AC voltage and measure the current through the primary then by using ohms law you can calculate the inductance. If you do try this approach be sure to use a sizable voltage (say 10V @ 60hz) to ensure enough excitation.
dave
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Follow Ups
- RE: -3db is 45 degrees phase shift, how much phase shift is -1db? (nt) - dave slagle 19:58:57 01/29/15 (1)
- Thanks Dave (nt) - Tre' 07:56:42 01/30/15 (0)