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220V live Wire-in-Wall scanner - This little circuit will help you
to scan line of a 220V live wire in wall. FET gate is
connected to a capacitive metal sensor (which is usually a simple metal
plate). When you hold sensor close to wall, LED will
indicate current flow around where it detects wire. Works on
9VDC.... [Peter Jakab, Electrical Engineer, Engineer of Informatics] |
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A Metal Detector for Pin Pointing - Preliminary ArticleMore to
come later....(design added 12/08) |
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A Simple BFO Metal Detector - A Very Simple "Beat Frequency
Oscillator" type of Metal Detector. These are about the Simplest of all
Metal Detector types, But still quite useful for many Detecting
applications. And although this one is particularly simple, I find it works
very well. For use outside on the ground the coil "MUST have a Faraday
Shield".... |
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Beat Balance Metal Detector (Rev Thomas Scarborough) - Various
embodiments of the BB metal detector have been published, and it has been
widely described in the press as a new genre. Instead of using a search and
a reference oscillator as with BFO, or Tx and Rx coils.... |
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CCO Metal Detector - To the best of the author's knowledge, the metal
detector shown here represents another new genre. It is presented here merely as an
experimental idea, and operates in conjunction with a Medium Wave radio….Elektor
Magazine…. [Published in issue 345, July 2005] |
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CCO Metal Detector - The metal detector shown here has, in concept, been
widely recognised as a new genre. The general concept, of which I have developed three
embodiments, is capable in principle of matching the performance of an Induction
Balance (IB) metal detector. This is the first embodiment to be released on the
Internet (the other two were published in Everyday Practical Electronics and Elektor
magazines). When this circuit is correctly set up, an old Victorian penny (30mm
diameter) should induce a shift in frequency of at least one tone on the Medium Wave
band at 140mm (5½"). Apart from using.... [Copyright Rev. Thomas Scarborough] |
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Coil Coupled Operation Metal Detector - The metal detector shown here has,
in concept, been widely recognised as a new genre. The general concept, of which I
have developed three embodiments, is capable in principle of matching the performance
of an Induction Balance (IB) metal detector. This is the first embodiment to be
released on the Internet (the other two were published in Everyday Practical
Electronics and Elektor magazines). When this circuit is correctly set up, an old
Victorian penny (30mm diameter) should induce a shift in frequency of at least one
tone on the Medium Wave band at 140mm (5½"). Apart from using.... [Copyright Rev.
Thomas Scarborough] |
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Metal Detector - This circuit detects metal and also magnets. When a magnet
is brought close to the 10mH choke, the output frequency changes. |
Metal Detector (Andy Collinson) - A single chip metal detector with a range
of a few inches. This is useful for decting nails or screws in walls and floors,
or for locating buried mains cable.
(electronic design added 09/02) |
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Metal detector (tomzi.geo) - A reasonably effective bfo (bifilar
oscillator). Its performance is not comparable to more advanced commercial products,
of course, but it still works. Anyway, during WWII metal detectors based on the same
principle were utilized my combat engineers of many armies to clear mines....(added
10/05) |
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Metal Detector based on the CS209Now Discontinued. - Especially Suited to
find studs in Walls. Note: this IC is discontinued and getting hard to
obtain....(electronic schematic added 12/08) |
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Metal Detector based on the TDA0161 - Preliminary Circuit Article....More
Info to Come....(Circuit design added 12/08) |
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Metal Detector for Pin Pointing - Preliminary ArticleMore to come
later....(design added 12/08) |
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Metal detector Mk1 - A fun metal detector to find coins at the beach…
(circuit added 05/07) |
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Metal detector Mk2 - More sophisticated 5 transistor metal detector (BC547,
BC557, BC338) (electronic schematic added 05/07) |
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Metal Detector uses Single IC - 12/12/97 EDN-Design Ideas....The original
application of the circuit in Figure 1 was to locate coins, but it applies wherever
you need to locate metal objects. The circuit uses a beat-frequency technique:
Whenever a metal object comes close to the search coil, the metal causes the coil's
inductance to decrease. Though the inductance.... [Design Idea by Rachel and Steve
Hageman, Hewlett-Packard, Santa Rosa, CA] |
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Metal Detector-A Pulse Induction Detector. Pulse-1 - Hundreds of this
Detector have been built with Very favourable Feedback....(electronic schematic added
12/08) |
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Metal Detector-Pulse-2 Induction Type Detector - This is a Revised Version
of the Pulse-1 above with Additional. Controls for More Flexibility. This
Project is Definately Not Recommended for the Beginner....(Circuit design added 12/08)
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My Metal Detector Coil Jig - Not a ProjectBut this is how I make the Flat
Coils....(design added 12/08) |
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New CCO Metal Detector - Thomas Scarborough has designed a new embodiment of
the CCO (Coil Coupled Operation) metal detector, a new genre which I invented in 2004.
I believe that this is the first IC design to appear on the Internet (there is a
transistor design on many websites, and IC designs were published by Elektor and EPE).
It took me just eight minutes to design this -- which illustrates the simplicity of
the principle. OBSERVATION: On the surface of it, it may look like an IB (Induction
Balance) detector -- but it is not. It works on the principle of the transformer
coupled oscillator (TCO), and requires an.... |
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Simple BFO metal detector - A Very Simple "Beat Frequency Oscillator" type
of Metal Detector. These are about the Simplest of all Metal Detector types, But still
quite useful for many Detecting applications. And although this one is particularly
simple, I find it works very well....(electronic design added 05/08) |
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Simple BFO Metal Detector - BFO ( beat frequency oscillator ) metal
detectors use two oscillators, each of which produces a radio frequency. One of these
oscillators uses a coil of wire that we call the search loop. The second oscillator
uses a much smaller coil of wire, and is usually inside the control box and is called
the reference oscillator. By adjusting the oscillators so their frequencies are very
nearly the same, the difference between them is made audible as a beat note....
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Simple metal detector Electronic circuit - (electronic circuit added 4/05)
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Testing Metal Detector Coils - I Decided to Check my coils for Inter-wire
and Total Capacitance. It is a Well Known fact that Internal Capacitance in a
coil reduces its frequency response. In the Tests Below, The coil Lead Lengths on all
coils was about 5 inches. No Coax cable used.... [G. L. CHEMELEC] |
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Two-component metal detector - The circuit shown must represent the limits
of simplicity for a metal detector. It uses a single 4093 quad Schmitt NAND IC and a
search coil -- and of course a switch and batteries. A lead from IC1d pin 11 needs to
be attached to a MW radio aerial, or should be wrapped around the radio. If the radio
has a BFO switch, switch this ON. Since an inductor resists rapid changes in voltage
(called reactance), any change in the logic level at IC1c pin 10 is delayed during
transfer back to input pins 1 and 2. This is further delayed through propagation
delays within the 4093 IC. This sets up a.... [Copyright Rev. Thomas
Scarborough] |
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