Re: Question on Q of toroid coil


"PeteS" <peter.smith8380@xxxxxxxxxxxx> wrote in message
news:B6fch.8825$s95.5318@xxxxxxxxxxxxxxxxxxxxxxx
PeteS wrote:
Homer J Simpson wrote:
"Dave" <db5151@xxxxxxxxxxx> wrote in message
news:12n24pardh3a6f6@xxxxxxxxxxxxxxxxxxxxx

Huh. A Q meter. This interests me. Any ideas on where I could find
info on building one of those? (I have a lot more time than money, and
it does sound interesting...)

They turn up on eBay from time to time. They sell for less than the
parts.




You can measure the Q of the coil by driving it at the frequency of
interest and measuring the phase angle between input and output.

Q = arctan phase angle

Cheers

PeteS
That should have read:

Q = arctan (90 - phase angle) = arccotan phase angle.

Cheers

PeteS

Now, *this* is really interesting. But how would you accurately measure the
two phase angles? Please share whatever information you have on using this
method of determining Q.

Thanks,

Dave


.

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