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From: c37189h@saha.hut.fi (Suomalainen Harri Olavi)
Newsgroups: sci.electronics
Subject: Re: Metal detecting revisited - hobby that pays for itself
Message-ID: <24539@santra.UUCP>
Date: 22 Aug 89 08:59:57 GMT
Sender: news@santra.UUCP
Reply-To: c37189h@saha.hut.fi (Suomalainen Harri Olavi)
Organization: Helsinki University of Technology, Finland
Lines: 10

The idea of metal detector is that when you place the coil near metal the
inductance of the coil gets higher in value. If the coil is used eg. in
an oscillator tank the frequency will be changed. If the coil is part of
an audio oscillator you'll notice the change in frequency. 

You could as well detect the inductance of the coil directly and be noticed
of metal as the inductance is changed.
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