Metal detectors

I agree with Cornelius - I am very interested in building a PI machine for prospecting/nugget hunting.  However, I have been hesitant in starting a project simply because there always seems to be conflicting information regarding the accuracy of the posted schematics and parts lists.  And few, if any of the projects have a well-detailed set of instructions for assembly, tuning and operation.

While I am not an electronics engineer of any sort, I have been building and modifying tube-based guitar amplifiers for two years.  I can read a schematic and "solder by numbers".  The huge difference I have found between the guitar amplifier community (and associated forums) and this forum is that the schematics and projects are clearly-described and well-supported with documentation in many cases.  Furthermore, the theory of amplifier circuits has been throughly dissected and digested to the point that a novice can easily gain a basic understanding of the "global circuit", as well as the functioning of the individual sub-circuits (i.e. power supply, preamplifier, power amplifier, etc) - thus allowing one to understand how the changing of component values on capacitors, resistors and the like alter the performance of the end-product.  That said, I challenge the "gurus" on this forum to assemble at least one accurate set of project files including the following:

- An accurate schematic
- An accurate parts list with suitable substitutes (especially for hard-to-find/obsolete parts)
- A clear and easy-to-understand set of instructions covering the details of assembly, testing & tuning, and basic operation...
- AND a basic "theory" paper (or primer) describing the overall circuit design, to include the design and function of the subcomponents (power supply, timing, delay, receiver, coil etc.). 

I know a good set of instructions would be very helpful to me.  So I strongly-suspect they would be beneficial to other novices interested in building a metal detector... Is anyone up to the challenge?!? 

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,12875.msg81583.html#msg81583

Hmmm... OK, Cornelius - then let me propose that you, and any other knowledgeable and willing member, please help me "dissect" the schematic for the DPB2010, for the purpose of education.  

How would one break down the schematic into individual sub-circuits?  And what is the function of each sub-circuit as part of the system?  Should we start this as a separate thread???

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,12875.msg81629.html#msg81629

Gold Digger, I do not accept your line of thinking. To avoid answering questions for the sake of avoiding follow-on questions makes no sense to me. I do not see such a collegiate-endevor being beyond the scope of this forum. The claims of "years of education" are just smoke to me. If you do not want to help the community by sharing knowledge and fostering understanding, so be it. But please do not deter others because you feel the material is too technical and intensive for the common man...

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,12875.msg81851.html#msg81851

GD - I have been studying basic electronics on my own.  As noted, I am not an engineer.  I would not even try to call myself a technician.  This is a hobby for me.  I have been building tube-based guitar amplifiers to 2 years now.  I knew nothing about electronics prior to that.  I learned everything from resources on the internet.  And most of my "education" was gained through forums similar to this one.  We all start out a clean slate.  If someone really wants to understand the intricacies of the electronics, he will seek out additional information on his own.  That is how I progressed from not being able to solder or read a schematic, to building amplifiers of my own design.  But my foundational-knowledge was gained from selfless-individuals who were willing and able to teach.

My point is this: Anyone can learn, given adequate instruction. I know this from experience, as I have taught university-level science courses for 2 years while earning my Master's degree.  I am merely trying to facilitate the creation of accurate and understandable instructional materials and resources here - that is my intent.  Thus, I have to disagree with your opinion on the topic.  I have no desire to battle with you - this has gone entirely too far in the wrong direction.

I honestly see the "dissection" of a PI schematic as a good place to start.  Being that Cornelius noted the DBP2010 is the most accurate and complete project, I found that to be a suitable platform for analysis.  And I welcome anyone willing to participate to help out.  If you find such an undertaking to be a waste of your time, do not bother.  There is no shame in not wanting to participate.  But why waste the energy saying it cannot be done? Just for the sake of saying "NAY!!!"?

That said, I will ask you to re-read Cornelius' original post in this thread, which - as I understand it, chastises those who sequester knowledge and essentially calls upon the experienced to share openly and completely with the members of the community... And I quote:

"I have seen many a schematic of metal detectors on this forum .  Sorry to say that most of the postings are not complete . We see a few pictures and boards . and some explanation . However I have not seen many ( not to say any ) complete schematics . Meaning  , a PCB  , a parts list , a placement schedule and information about the coil . Sofar I have only seen information that makes it nearly impossible to build a detector . Why are the guys that are willing to inform us not giving us the complete information . Do they just want to keep that for themself ? I would say , if you do not want to share ALL the info necessary to build a detector , don't give anything .  The only one I noticed giving complete info is Darkkitten  . He is not holding anything back ,  as it should be  . Xavier is another willing to help you . Eugene is only passing on tit-bits of info and always states that he will give some more info later .  Just my opservation .   Cornelius"

Best regards - Peabody

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,12875.msg82152.html#msg82152

		Quote:			Posted by peabody
	GD - I have been studying basic electronics on my own.  As noted, I am not an engineer.  I would not even try to call myself a technician.  This is a hobby for me.  I have been building tube-based guitar amplifiers to 2 years now.  I knew nothing about electronics prior to that.  I learned everything from resources on the internet.  And most of my "education" was gained through forums similar to this one.  We all start out a clean slate.  If someone really wants to understand the intricacies of the electronics, he will seek out additional information on his own.  That is how I progressed from not being able to solder or read a schematic, to building amplifiers of my own design.  But my foundational-knowledge was gained from selfless-individuals who were willing and able to teach. My point is this: Anyone can learn, given adequate instruction. I know this from experience, as I have taught university-level science courses for 2 years while earning my Master's degree.  I am merely trying to facilitate the creation of accurate and understandable instructional materials and resources here - that is my intent.  Thus, I have to disagree with your opinion on the topic.  I have no desire to battle with you - this has gone entirely too far in the wrong direction. I honestly see the "dissection" of a PI schematic as a good place to start.  Being that Cornelius noted the DBP2010 is the most accurate and complete project, I found that to be a suitable platform for analysis.  And I welcome anyone willing to participate to help out.  If you find such an undertaking to be a waste of your time, do not bother.  There is no shame in not wanting to participate.  But why waste the energy saying it cannot be done? Just for the sake of saying "NAY!!!"?

So now you are imputing a motive to my suggestion that you learn on your own? Shame on you. I am a former instructor in advanced electronics. I'm speaking from experience. Asking for someone to analyze and write up a theory of operation on such a complex design such as this is asking more than just a tiny little favor. A book could be written on it and you'd be just as lost as if you stared at it wishing for some sort of karmic understanding.

		Quote:			Posted by {author}
	That said, I will ask you to re-read Cornelius' original post in this thread, which - as I understand it, chastises those who sequester knowledge and essentially calls upon the experienced to share openly and completely with the members of the community... And I quote: "I have seen many a schematic of metal detectors on this forum .  Sorry to say that most of the postings are not complete . We see a few pictures and boards . and some explanation . However I have not seen many ( not to say any ) complete schematics . Meaning  , a PCB  , a parts list , a placement schedule and information about the coil . Sofar I have only seen information that makes it nearly impossible to build a detector . Why are the guys that are willing to inform us not giving us the complete information . Do they just want to keep that for themself ? I would say , if you do not want to share ALL the info necessary to build a detector , don't give anything .  The only one I noticed giving complete info is Darkkitten  . He is not holding anything back ,  as it should be  . Xavier is another willing to help you . Eugene is only passing on tit-bits of info and always states that he will give some more info later .  Just my opservation .   Cornelius" Best regards - Peabody

I'm not suggesting that you give up your pursuit of knowledge, my friend. Just that you ask smaller questions. Ask about what this circuit or that does. When you get an answer, amazingly, other circuits may become apparent. In this case, you asked and got an answer then developed the next answer yourself. For example, there is a divide by 10 counter in one of the detectors on these forums. Asking why it's there is a valid question. Asking for the entire circuit to be analyzed is like me asking to to please rebuild my car engine as a favor because you know a lot about car engines.

We moderators are here to give minor assistance, not build your next detector for you or give you a diploma in electronics. What you asked and are asking for now is beyond the scope of a forum. A private tutorial, no worries, but if you ask for that, you might want to consider paying for it.

Join a Ham Radio class in your area. They're out there. You will learn all you need to know from those reasonably priced courses.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,12875.msg82201.html#msg82201