4 posts in this topic
New White's Patent - Constant Current Metal Detector
By Steve Herschbach
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:
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?
Half Sine Metal Detector Technology - Hybrid Induction Balance / Pulse Induction Metal Detector
By Steve Herschbach
I always have my ears perked up for something new in metal detectors and metal detecting technology. I confess to not being smart enough to really get deep into the technical side of it but I have a general layman's knowledge of the subject.
A couple years ago Carl Moreland, the Engineering Manager for White's Electronics, was interviewed on a radio show. I tripped over a reference to the interview on another forum and checked it out. It is very long, and near the end Carl dropped a bombshell. At least I thought so, but it went unnoticed and uncommented on in the metal detecting online world. I thought about posting it on a forum back then but decided to wait and see what developed. Here is the applicable portion of the interview:
Relic Roundup Radio Show, January 17, 2012, Interview with Carl Moreland, Engineering Manager, White’s Electronics
Transcript beginning at 50:57 mark:
Carl Moreland - “I can mention one technology that we’re working on because the patent has already been published… or the application, not the patent hasn't gone through yet. We’re working on something called half sine technology, which has actually been around since the 1960’s in geophysical prospecting applications. This is where instead of transmitting a sinusoidal signal you actually just transmit half of the sine and you can do that at extremely high voltages and high ? rates and so on. It’s technically not pulse induction but it’s not VLF either and it is a time domain method. And with that we can get really good depth and we can even get target id information and do discrimination and so forth.”
Can you see why I perked up at that? I am still amazed it did not get any notice at the time. Nothing happened for a long time. Then I got this PM from Rick Kempf recently:
Sent 29 January 2014 - 09:04 AM
Was looking for info on my new SD 2100 this AM when I sort of fell down a rabbit hole of old forum posts and emerged reading Whites new patent. About the first thing I noticed was that you were cited in "prior art".
Here's what they cited: http://www.voy.com/76600/7/475.html
The patent is here: http://www.google.com/patents/US20110316541
Is this something you knew about? Just wondering.
I told Rick, yeah, heard about that. It was the patent finally being granted from the application Carl mentions in the interview. It was fun getting a mention in a patent though I think it was just the examiner studying up on the subject and finding my old post helpful in simplifying the subject.
For a long time the Holy Grail in metal detecting has been something that combines the target identification of an Induction Balance (IB or more commonly known as VLF) detector with depth of a Pulse Induction (PI) detector. There have been many promises and false starts over the years, and that was one reason I kept the radio interview mention quiet the last couple years. Frankly, I had half forgot about it until Rick brought the patent being granted to my attention. Notice the title:
Hybrid Induction Balance/Pulse Induction Metal Detector
A new hybrid metal detector combines induction balance and pulse induction technologies. Target signals are generated from a transmitted wave that has both induction balance and pulse current inducing characteristics and uses pertinent sampling of the receive data. Combining the two data sources provides eddy current target identification while excluding ground permeability and remanence obscuration.
Is it time to sing Hallelujah? Well, there is a big gap in between getting a patent and bringing a detector to market. Many patents get filed and you never even see something directly related to the patent. Maybe it looked good on paper but does not pan out well in reality for numerous reasons. So just because White's was granted this patent does not mean something is around the corner. However, they have been working on it for over two years already obviously. And it has been some time since White's put something new out. I do not count remakes of the MXT etc as new. So I think there is reason to be hopeful we may see something one of these days.
John Earle is one of the unsung heros in the industry. He had a hand in many of the best products at Compass Electronics before moving over to White's after Compass went under. To this day I have never used a VLF that goes any deeper than my old Compass Gold Scanner Pro. John was one of the brains involved in that, as well as the White's Goldmaster 3, regarded by many as being the pinnacle of the analog development of that model line. I was fortunate to have met John at the factory some years ago. He is listed as the inventor on the new patent. Half sine technology is also mentioned in an earlier patent filed by White's, again with John listed as inventor at http://www.freepatentsonline.com/7649356.pdf
Looks like serious stuff brewing. Bruce Candy of Minelab makes mention of half sine technology in a patent application at http://patents.com/us-20130154649.html which makes me wonder about the new "Super Gold Detector" he is working on. But it is this most recent patent by White's that seems to put the finest point on it. Maybe the Holy Grail of detecting is soon to be a reality. The fact it is White's certainly gives me more hope than what we have seen in the past.
Edit May 2015 - see also White's patent for Constant Current Metal Detector
Jimmy Sierra Fired
I just got this In an Email and I am very shocked because Jimmy has been working with Whites for so long and he was one of the Major Guiding Lights behind The GMT and The MXT, all I can say is I am sorry to see this happen.
Bless You Jimmy, you always gave us the Time of Day.