Just curious, is this the Pulse Devil patent?

[FrankMD]

http://www.faqs.org/patents/app/20090045813


The discrimination technique looks very interesting.

HH

Frank

 

[goldprospectinginoz]

No, its not the Pulse Devil Patent
If you want to know what is happening with new detectors like the USA designed Goldsweeper discriminating Pi or some other Oz designed detectors like the QED and the MPI then have a look here:

http://goldprospecting.invisionplus.net/?mforum=goldprospecting&showforum=76
http://goldprospecting.invisionplus.net/?mforum=goldprospecting&showforum=71

cheers,
Goldprospectinginoz

 

[goldprospectinginoz]

Here is a link to Allan Westerstens Goldsweeper Patent
http://v3.espacenet.com/publicationDetails/originalDocument?CC=US&NR=2008224704A1&KC=A1&FT=D&date=20080918&DB=EPODOC&locale=en_EP
and a link to one of Allan Westerstens coil patents
http://v3.espacenet.com/publicationDetails/originalDocument?CC=US&NR=2006164105A1&KC=A1&FT=D&date=20060727&DB=EPODOC&locale=en_EP
cheers,
goldprospectinginoz
http://goldprospecting.invisionplus.net/

 

[Jackpine Savage]

then that patent of his is worth some bucks. Would it be possible to apply the same theory (not use the X component) to VLF's? Sorry if that is a stupid question!

Tom

 

[goldprospectinginoz]

I do not know the answer to your question,The inventors would be the best folk to ask.
cheers.
Goldprospectinginoz

 

[Prospector_Al]

Hi Tom,

In principle, the same technique can be applied to a VLF detector, but compensating for the reactive signal is a bit more complicated.

In the original patent, the coil system is balanced during a linear current ramp. Unbalance causes a signal that is just a DC level. In the case of a VLF detector, coil system unbalance caused by ground signals generates a sinusoidal signal. A sinusoidal signal can not be eliminated by just a pulse of the appropriate magnitude and polarity--it must be neutralized by a sinusoidal signal that has the correct magnitude and phase relationship with the offending signal.

I'm working on a solution to that problem at this very moment. I call this a "Hybrid-Technology" metal detector. The idea is to use the advantages of both the PI and VLF technologies at the same time.

If I'm successful, you'll see a patent application for this technology appearing soon...

Best Regards,

Prospector_Al

 

[Jackpine Savage]

Hi Al,

Thanks for the reply. My good fortune is to live in an area that for the most part has very low fe mineralization. However, seasonal and weather related changes to soil (resistivity?) conditions definitely have an effect on VLF performance. My understanding is that current PI designs main advantage in mild ground is simply due to the fact that they can use larger coils. But that leaves one with no discrimination!

My hope is that a hybrid design will come along that ups the ante for those of us that are lucky enough to have "good ground".

HH Tom