northwest anti interference coils: are they the way to go?
Welcome, Guest. Please login or register.
Tuesday June 18 2019 00:35:52 AEST AM
Home Help Login Register
News: Welcome to the Australianelectronicgoldprospectingforum founded in July 2010, an add free totally independent forum with over 70 boards and paid for and managed by the Admin.Topics: 9,245  Total forum Posts:46,357 Members:816. Total page views:12,263,130  Admin and  forum and domain name owner :marjen at optusnet.com.au. Guests can only see a limited number of boards at present and cannot see any hot links. Guests cannot post and never will be permitted too!Registration of new members must be approved by admin.
 All  original Photos and posts and  original materials displayed on this site are COPYRIGHTED and remain the property of the poster and the  Austalian electronicgoldprospectingforum.com. All messages on this forum express the personal views of the author and should not be interpreted as necessarily being in accord with those of the forum owner and neither the owner of this forum and its domain name nor SMF or the forum software developers or the forum host shall be held responsible for the content of any message. Admin reserves the right to remove any offensive or objectionable posts. No defamatory material or politics/religion or issues of race will be permitted.
QED news
New GB timing algorithm being tested in the QED.
Climate news
Contribution to global warming by Australia. Australia has one of the highest per capita emissions of carbon dioxide in the world, with 0.3% of the world's population it produces 1.4% and rising(not the .08% the  finders forum dope "Inhere" claims!) of the world's greenhouse gases. Australia also has the highest per capita emissions in the OECD, with 26 tonnes of greenhouse gasses being emitted per person every year.
Australia's C02 emissions rise for the 4th year in a row.

australian electronic gold prospecting forum.com  |  Detector Technology and Electronics and new detectors  |  Detector Coils (Moderator: Goldman)  |  Topic: anti interference coils: are they the way to go? 0 Members and 1 Guest are viewing this topic. « previous next »
Pages: 1 2 3 4 [5] Go Down Print
Author Topic: anti interference coils: are they the way to go?  (Read 7106 times)
Aziz
invited members
Supreme Hero Member
****
Offline Offline

Posts: 3977



« Reply #80 on: Thursday November 25 2010 07:24:53 AEDT AM »

Hi all,

there are many possibilities to achieve a good EMI rejection. Every solution has it's own benefits and drawbacks.

It is very important, that the EMI cancelling coil should be of same characteristics of the receive coil. Particularly, the damping resistor and the EMI cancelling circuit can degrade the EMI rejection ratio heavily.

I have a good and simple solution, but it has a frequency dependent rejection ratio. It's rejection ratio is superior for low frequency EMI and is getting worse on higher frequencies.

Nevertheless, the best solution is already published and is well known. The fundamental requirement for a good EMI cancelling is:
- EMI source is usually equal coupled to both coils (RX, EMI coil). This means, the receive coil and the EMI cancelling coil is inducing the EMI at same voltage level and phase (in-phase or anti-phase). The phase is one of the most important one.
- Target is different coupled to the coils. The EMI cancelling coil should have almost no coupling to the receive coil or target (ideally 0).
- EMI cancelling coil should be of same characteristics to the receive coil. And the EMI cancelling circuit should not cause any inbalance to the coil characteristics.

Aziz
Logged

Free science, knowledge and inventions to the mankind.
IBGold
invited members
Junior Member
****
Offline Offline

Posts: 480


IBGold at home.


« Reply #81 on: Thursday November 25 2010 16:43:52 AEDT PM »

Hi Doug I have tried that design and one with 4 RX coils and was not impressed but that picture almost looks like my latest IB RX coil not exactly but similar Aziz will understand Prototype is almost complete so we will find out when I go field testing four new designs.
Regards, Ian.
Logged

Regards, Ian.
ozzygold
Guest
« Reply #82 on: Monday June 6 2011 10:23:25 AEST AM »

Hi
Do you need to use a resistor if making a simple figure of 8 AI coil for a TDI? Or just make a normal coil and twist into the 8 shape? I have areas at hand with salt lakes and very mineralised ground.
Logged
Doug
Administrator
Revered Supreme Hero Member
*******
Offline Offline

Posts: 16715



« Reply #83 on: Monday June 6 2011 10:30:03 AEST AM »

  
Hi Doug I have tried that design and one with 4 RX coils and was not impressed but that picture almost looks like my latest IB RX coil not exactly but similar Aziz will understand Prototype is almost complete so we will find out when I go field testing four new designs.
Regards, Ian.

Look forward to the results because I believe that anti interference coils have a lot to offer both for  EMI rejection and for salt lakes.Unfortunately one limitation of them tends to be in very hot, variable ground where, because of the way they work  I found them more noisy than a DD and in some cases as noisy as a mono.
doug smile
Logged

All posts on this forum are the personal views of the author and should  not necessarily be  interpreted as those of Admin.
When is 1halfgram4three (a proven forum hacker and  village idiot!) going to stop telling lies on his “forum”?
mikebg
invited members
Newbie
****
Offline Offline

Posts: 153



« Reply #84 on: Monday June 6 2011 14:30:21 AEST PM »

The idea for good distance between RX coils mentioned in reply #27 and the idea for rotation axis at flourish shown in reply # 40 was implemented in 1924. I think the attached circuit diagram can suppress not only EMI, but also the GND signal.


* 1924.gif (108.03 KB, 558x883 - viewed 255 times.)
Logged
WM6
invited members
Senior Hero Member
****
Offline Offline

Posts: 1978



« Reply #85 on: Sunday December 11 2011 01:47:52 AEDT AM »

  

. I think the attached circuit diagram can suppress not only EMI, but also the GND signal.


Maybe on some terrains but there are terrains which soil condition changes at smaller distance than distance of such coils.
Logged

Global capital is ruining your life?
You have right to self-defence!
Aziz
invited members
Supreme Hero Member
****
Offline Offline

Posts: 3977



« Reply #86 on: Sunday December 11 2011 02:17:15 AEDT AM »

  
The idea for good distance between RX coils mentioned in reply #27 and the idea for rotation axis at flourish shown in reply # 40 was implemented in 1924. I think the attached circuit diagram can suppress not only EMI, but also the GND signal.

This f.... prior art definitely infringes the ML patent!
BL!$&$§$%FU!%&§%BA!$§% (they shouldn't invent it before ML).
 Clown
Aziz
Logged

Free science, knowledge and inventions to the mankind.
Pages: 1 2 3 4 [5] Go Up Print 
australian electronic gold prospecting forum.com  |  Detector Technology and Electronics and new detectors  |  Detector Coils (Moderator: Goldman)  |  Topic: anti interference coils: are they the way to go? « previous next »
Jump to:  


Login with username, password and session length

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2006-2009, Simple Machines
Simple Audio Video Embedder

BisdakworldClassic design by JV PACO-IN
Valid XHTML 1.0! Valid CSS!