Jump to content

New White's Patent - Constant Current Metal Detector


Recommended Posts

I do wonder what is up at White's Electronics. They have not put out a new detector platform since the V3i in 2009. Just rehashes of the MXT mostly. Yet they have been extremely busy on the research front, with the patent issued on half sine technology earlier this year http://www.detectorprospector.com/forum/topic/118-half-sine-metal-detector-technology-hybrid-induction-balance-pulse-induction-metal-detector/

And now a new patent for a constant current metal detector:

http://www.google.com/patents/US8878515

United States Patent 8,878,515
Earle November 4, 2014

Inventors: Earle; John L. (Sweet Home, OR)
Assignee: White's Electronics, Inc. (Sweet Home, OR)
Family ID: 51798186
Appl. No.: 13/235,916
Filed: September 19, 2011

SUMMARY OF THE INVENTION

The new invention provides better target object characterization and identification while eliminating ground mineralization detection.

A constant current in the energizing coil establishes a constant magnetic field that goes from zero to a strong, but constant, field very rapidly, as in less than 10 microseconds. Target objects such as coins and other eddy current objects have an energizing time constant usually exceeding 10 microseconds, wherein the eddy currents accelerate until field equilibrium is reached in the target object.

A constant current or constant magnetic field does not produce a significant signal in a receive coil after the transition from zero to constant current from ground mineralization permeability (powdered iron or ferrite equivalent). Target object eddy currents do produce a signal of varying amplitude throughout the constant current period, depending upon eddy current charging time or inductance of the object, usually not a simple exponential due to configuration of the target object. i.e., diameter, thickness, conductivity, etc.


It will be interesting to see if these patents result in any actual product. People often make the mistake of thinking a patent means something is ready to hit the shelves and the truth is just the opposite. Patents are often filed and nothing ever comes of it. Or it gets licensed to others, who actually produce the goods. Who knows what is going on in this case, but White's is obviously still attempting to move the technology forward. I hope the best for them as they are an old name in the business and a great bunch of people.

What makes this doubly interesting is Minelab also has patents in the works on constant current technology. http://www.detectorprospector.com/forum/topic/311-minelab-bruce-candy-new-patent/?p=2291 The Minelab work is an application for patent that has been in progress since 2009. This White's deal is an actual patent granted. Is there conflict here? Obviously with these two big names at work on the same thing something is up. Sad story is I am not well versed enough in the technology end of things to truly understand how this may actually improve metal detectors for the end user. Other than what it says up above - better discrimination while eliminating the ground. How much better is better?

  • Like 1
Link to comment
Share on other sites


  • 1 year later...

Time to revive this one, now that I can explain what the heck this is. What this is basically is another way to do a detector similar to a GPZ 7000. Both are constant current applications but approached two different ways. The question being, is one superior to the other? Only time will tell, but it is only this and the half sine patent, also from White's, that offer a serious possibility of rocking Minelabs boat.

  • Like 2
Link to comment
Share on other sites

Thanks Steve for keeping us updated on the latest happenings in World of Detectors.  

Link to comment
Share on other sites

The circuit in the patent looks simple. I could only fine one image. However, patents can be deceiving. The science is fantastic. The design of the actual circuit will be far more complex. All I can say to John Earle is, "Great Job". It's now up to White's to take the idea and run. If I read and understand the patent correctly. A lot for a old retired electronics engineer to take in. We will be seeing a future White's machine with greater depth and more accurate discrimination. Possibly a 2D or 3D screen to show the target and trash in the ground. It won't be cheep!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...