1. Home
  2. Electronics Design
  3. Concentric PCB Induction Balanced Coil for Metal Detectors

Concentric PCB Induction Balanced Coil for Metal Detectors

Concentric PCB Induction Balanced Coil for Metal Detectors

Hello,

I am using a concentric printed circuit induction balanced coil (ca.

20 cm diameter) for a metal detector and had phantastic measuring results:

- very low temperature dependency (size invariant design)

- very thin dimension (ca. 3 mm)

- very easy to build (just making a pcb-board)

- no balancing needed (computer designed geometry - thus automatically balanced)

- most of the area is for the rx-coil

- combined small rx and big rx-coil (due to the geometry, the rx-coil is a spiral from the inner side to the outher side)

- bigger transforming effect (nummer of turns for rx-coil is much more then for the tx-coils), to reduce the gain of the amplifier, thus reducing also noises of the amplifier.

Therefore, it is very sensitive even to small metal objects (nuggets).

Attention: By disclosuring of such an induction balance PCB coil now, it is not any more possible to patent such pcb ib-coils. Especially, this kind of pcb-ib-coils containing four coils, big receiver coil area, 1 winding ground balancing/fine balancing coil, transmitting coil and canceling coil. Disclosure Date and Time: First Disclosure: 4. March 2005, 10:08 MEZ Updated: 10. March 2005, 15:01 MEZ

If you want to the the sensor (search coil), just follow the link below:

formatting link

original image:

formatting link

Some details:

20 cm diameter 600 DPI Resolution

from the inner coils numerated

- rx-coil

- canceling-coil

- one winding coil for special use (ground balancing coil / fine balancing)

- tx-coil

Aziz

PS: May be your browser cannot show such a big image. Just download the image and use an image-viewer.

Reply to
Aziz
Loading thread data ...

You need to test links before posting them. You can't deep-link to anything on Tripod.

Reply to
JeffM

So where's the schematic? Or the complete article? There are only pictures and as Jeff put it, blather. Very confusing. Concentric rings on a PCB... sounds an awful lot like a Flux Capacitor... careful, it might warp right off your desk!

Reply to
Mark Jones

The performance statements are a little light on numbers too. How far can it see a 10 penny nail? How far can it see a soda can?

BTW: Metal detects see modest sized objects to depths of about 2 times the diameter of the head at best. Very large objects such as burried solid copper box car can be seen a little deeper.

--
--
kensmith@rahul.net   forging knowledge
Reply to
Ken Smith

I read in sci.electronics.design that Ken Smith wrote (in ) about 'Concentric PCB Induction Balanced Coil for Metal Detectors', on Fri, 11 Mar 2005:

I suppose they are very common in USA.

--
Regards, John Woodgate, OOO - Own Opinions Only. 
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
Reply to
John Woodgate

If you look closely there are no concentric rings. They are spirals, which are used as inductance coils.

That pcb board with etched coils is what sits inside the circular search head you move over the ground to hear what metals are in the ground. That circuit board is big, something like 20cm in diameter.

(At first I thought is was a hypnotic joke picture. But as I zoomed out I saw the coils.)

--
Roger J.
Reply to
Roger Johansson

A little like the central portion of the first Black Sabbath LP perhaps.

Reply to
richard mullens

Yes they often show up in such discussions on this side of the Pond.

--
--
kensmith@rahul.net   forging knowledge
Reply to
Ken Smith

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.