Delta Pulse

[greylourie]

Hi All,
What I am most interested in finding is small gold..! if I can locate even small amounts then I can at least clean up with panning. I already own a VLF machine which is great for the odd coin shooting at the beach but it is totally useless on the gold fields..! I experimented about 10 years ago with the older designs and have been keeping a watch full eye on the progress on the net and the forums and feel that now is a good time to revisit.
My ultimate aim is to develop a PI which can discriminate between ferrous and non ferrous metals and I have already seen that the PI has the capability to do this and I am willing to work through the current designs available now and to experiment later. When I mentioned stable performance what I was trying to say was that I was looking for a design that provided the SAT with good ground cancellation and the MiniPulse clearly solves both of these issues. I am still trying to understand the Delta Pulse circuit but it seems to me that it also provides a SAT just that I can not work out how it compensates for the ground.
I have spent the weekend reading the book "Inside the Metal Detector" by Carl Moreland and George Overton and would highly recommend this book to anyone wishing to develop their own design.
I like the George Overton design because it is easy to experiment between dual and single coil configuration, I understand the circuit and it is simple to set up and use so will try this first.
I would also welcome some more information regarding the operation principles of the Delta Pulse as I like the performance I have seen so far on youtube just that I am finding it difficult to understand the circuit mainly because I do not have any information regarding the T2, T4 and T5 timing so I will consider to put this into Proteus if need be.
For the time being it is my intention to evaluate two or three designs and to eventually convert one of these with MCU and provide some more adjustments by way of a digital encoder and display and to eventually experiment at adding software routines to add discrimination.
Q - Regarding the Minipulse design I note that in the book by CM and GO they recommend to use a 4066 instead of JFET's. Do you think the sampling integrator would benefit by replacing the JFET's with a 4066..?

Hello Sean,

The minipulse looks like a very good experimental platform, and Qiaozhi aka G.O has produced some very nice documentation to go with it. But dont rule out vlf entirely. A Geotech member built a very nice, ground-balancing vlf. He was very pleased with its response to small gold nuggets.

You can find his posts here : http://www.geotech1.com/forums/showt...568#post170568

Also you might be interested in the Goldscan threads on Geotech. Posts by Max, Reg and Jose' give lots of tips on constructing what is in effect, the predecessor to the TDI.
And Jose' has posted youtube clips of his homebuilt Goldscan here : http://www.youtube.com/watch?v=GEd9_...ature=youtu.be

[kt315]

SORRY Orbit, BIG sorry, but DP is not needed in additional adwertizing, esspecially from you. it is classic full analog PI static advanced design, no PR action from you now,
leave please this thread. I am not the authour of the DP, I know that two bulgarians gave this schematic to our world and Glory to them! but again,
this is not their design but of somebody from Germany.

Kind regards

[Orbit]

What do you think Why him Golden Mask him ,Ask Vladimir or see the Bulgarian site Imperio What he says Vlado all the best KT !BANDITO-PULSE_engl.pdf and yet this, Bandito Pulse schematically more (dbp 2010 or detective ) but less delta pulse If I understand correctly Vladimir ..

[Orbit]

And this is after you graund balance there really eliminate something cut down on but it is not Ground balance attempt to eliminate the red brick so let me know kt I'm very disappointed I'm your more appreciated,I thought that the more you know about pi detectors !.

[Dean Sarelius]

Hi KT315,
Thank you for providing the timing it is much appreciated.
I will take a closer look at this now and look forward to share my results..!
Kind regards,
Dean

[Qiaozhi]

Q - Regarding the Minipulse design I note that in the book by CM and GO they recommend to use a 4066 instead of JFET's. Do you think the sampling integrator would benefit by replacing the JFET's with a 4066..?

The Minipulse Plus is a complete working design as it is presented in the REV-B data.
However, it is designed to be simple to build, understand and get working. For those that want to experiment further, then it represents a good platform for that purpose. That have already been lots of questions concerning possible equivalent parts, etc. My reply to these questions is simply this:
Build the Minipulse Plus and get it working as is. Then build a second unit on which you can experiment, and make comparisons with the original board. If you have any success with your various updates and modifications, please post them in the Minipulse Plus thread.

Whether replacing the FETs with analog switches would provide any noticeable performance improvements or not is probably open to debate. Please feel free to try it and report back with the results.

[kt315]

T2, T4 and T5 timing
---

[kt315]

Dean if you want to discriminate using PI have a look at the Chance PI.

one PI CAN discriminate and you good know that the QED is restricted by minelab trolles here. moderators are not able to save the Project from agression
from the trolles and to ban them in moment. Chance is closed project of Andy, he did return out on VLF design (Quazar).

[kt315]

please read those simple rules for first you only get the board from me.

[Silver Dollar]

Dean if you want to discriminate using PI have a look at the Chance PI.

[kt315]

dp pulse does not graund balance Ground balance is done the two channels etc.Look a little more forum !

bla-bla-bla. and zero of information like always. read the F manuals of DP. look a little more forum YOURSELF.

[Dean Sarelius]

Hi All,
What I am most interested in finding is small gold..! if I can locate even small amounts then I can at least clean up with panning. I already own a VLF machine which is great for the odd coin shooting at the beach but it is totally useless on the gold fields..! I experimented about 10 years ago with the older designs and have been keeping a watch full eye on the progress on the net and the forums and feel that now is a good time to revisit.
My ultimate aim is to develop a PI which can discriminate between ferrous and non ferrous metals and I have already seen that the PI has the capability to do this and I am willing to work through the current designs available now and to experiment later. When I mentioned stable performance what I was trying to say was that I was looking for a design that provided the SAT with good ground cancellation and the MiniPulse clearly solves both of these issues. I am still trying to understand the Delta Pulse circuit but it seems to me that it also provides a SAT just that I can not work out how it compensates for the ground.
I have spent the weekend reading the book "Inside the Metal Detector" by Carl Moreland and George Overton and would highly recommend this book to anyone wishing to develop their own design.
I like the George Overton design because it is easy to experiment between dual and single coil configuration, I understand the circuit and it is simple to set up and use so will try this first.
I would also welcome some more information regarding the operation principles of the Delta Pulse as I like the performance I have seen so far on youtube just that I am finding it difficult to understand the circuit mainly because I do not have any information regarding the T2, T4 and T5 timing so I will consider to put this into Proteus if need be.
For the time being it is my intention to evaluate two or three designs and to eventually convert one of these with MCU and provide some more adjustments by way of a digital encoder and display and to eventually experiment at adding software routines to add discrimination.
Q - Regarding the Minipulse design I note that in the book by CM and GO they recommend to use a 4066 instead of JFET's. Do you think the sampling integrator would benefit by replacing the JFET's with a 4066..?

[Orbit]

dp pulse does not graund balance Ground balance is done the two channels etc.Look a little more forum !

[6666]

Hi KT315

I see in your latest DP schematic that R9 plus 500K pot is labeled as ground balance.
How well does the ground balance work ?
Thanks.

[Qiaozhi]

I can find tonns of video in which DP used for coins' hunting. no big problem to re-tune DP for coins or gold nuggets (C4 C5 ---> 1nF, R7 ---> 10k). DP has one-stage preamp working in SAT mode - this done for increase of all stability of the schematic. Minipulse, Surf PI, Baraccuda PI have not PULSE WIDTH tuning, ie you can not simply increase
the TX power in them (related directly with the depth).

I don't know what Dean Sarelius is wanting to search for with the detector, but I would be interested in seeing a video of a DP being used to find gold nuggets. There doesn't appear to be anything on youtube.

By the way, the Minipulse Plus has been designed for simplicity of construction, and therefore it doesn't have lots of knobs to adjust, or options that need to be set. However, if someone did want to be able to adjust the pulse width, then this could easily be accommodated by fitting an external pot. Personally I'm hoping that others will modify the design to either add extra features (such as ground balancing) or customize their units to suit their own needs, as it's flexible enough to allow further experimentation. It should even by possible to use large search frames if the TX pulse rate and width are adjusted accordingly (plus the addition of a suitable heatsink on the mosfet). I can think of lots of possibilities.