DIY 22uH Choke using Torroid Core?

Look at the pictures in the data sheets and see if they are good enough to estimate the number of turns?

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These are my opinions, not necessarily my employer\'s.  I hate spam.

Hop on over to

and download their free ring-core calculator. Not much help if you don't know the material, though it does show color codes for iron powder.

Depends on what test equipment you've got handy; I'm guessing not an LCR meter. But with sine wave source, some resistors, and a DMM you should be able to get pretty close to the 3 dB-down point for an LR filter by adjusting the frequency or resistance, or both.

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Rich Webb     Norfolk, VA

has formulas for calculating inductance from turns, area, etc, near the bottom of the page.

Wild guess (I don't know the length of your core or it's K factor) is

42 turns.

Rich Webb expounded in news: snipped-for-privacy@4ax.com:

Hey, that is perfect, thanks.

Between the dimension information and the colours, I think I have what I need.

Warren

No. A grid dip meter is a coil+meter unit brought close to a tuned circuit. By sweeping frequency, you can find where the "dip" occurs (hence resonance). If you know C and f, you can determine L. But the software approach above, is more to my liking as a starting point at least.

Ya, I should try that out and see how close I got.

Warren.

Conceivably this may help. Identify the core and it'll calculate it for you.

Graham

Graham