Delta Pulse

[ramin]

you are right

No problem with battery consumption

Battery consumption at maximum pulse width is about 400 mA

i use a 2300 ma lead acid battery

But there is another problem

When I set the pulse width to above 250 microseconds, the dp starts beeping unnecessarily, especially when I close my hands to the box.

I have to say that I completely shielded the box even all volumes and keys

But in my opinion this is an undeniable subject

Even with a pulse width below 250 microseconds, the detection depth is great

A couple of days ago I went treasure hunting with DP 110 *110 cm frame coil

As a result, I found a can(8*13cm iron aloy) at a depth of 70 cm while the frame was at a height of 40 cm above the soil surface.

There was 20 cm of snow on the soil surface

And the frame was 20 cm above the snow

The can was 70 cm below the ground, and I think the can was there for many years

In total, the distance between the coil and the can was about 110 cm

The DP reaction was very weak but every time I passed above the target point the dp had reaction

I had adjusted the first delay so that it would not respond to small targets like nails

[Vadim18]

If i proper understand, you telling about Autoreset at power on, this is 100% must have.
My addition will help to limit or fine tune reset button to not let "over do" reset work.

[kt315]

you need pressing RESET, i do not. second pic shows how mod works.

[Vadim18]

My small contribution to Delta Pulse (D.P.) "Reset Depth" addon.

Problem
long time for treshold recovery needed after pressing "RESET" button, which are usualy more than 5 seconds.
Final sensitivity in D.P. are very treshold level dependable. Sensitivity are optimal when VCO click rate are about 1-2 Hz, which is corresponds to more than +1 volts on pin 7 (D7B)
Reset button usualy do deep reset, down to minus 0.3 volts on pin 7 (D7B), thus long time needed for recovery to optimal voltage and click rate.

Solution
Added trimpot R 22К to negative feedback loop, to adjust final "reset state" voltage on pin 7 (D7B).

Changes in schematic

[kt315]

see rocky pulse

[waltr]

Hello everyone, because the microcontroller and the 12v power supply cannot share the ground, the microcontroller output is only 3.3 volts. How to drive the irf740 through circuit conversion?

NPN transistor.Check how I did this on my HH2.

https://www.geotech1.com/forums/showthread.php?24251-My-take-on-the-HH2

[liudengyuan]

Hello everyone, because the microcontroller and the 12v power supply cannot share the ground, the microcontroller output is only 3.3 volts. How to drive the irf740 through circuit conversion?

[kt315]

hi amigo

I made dp and it's a perfect metal detector

good news.


Now I made a 110*110 cm coil without shield for Dp and it works very well

to shield of same coil is hard job and not needed because we have a coil with lowest resistance.
such coil itself is good shielded via 'cold' end.

But i made another one, I used a shielded cable i connected the two end of shield

but when i test the dp with this I had to adjust the first delay width at high point and the main pulse width at low point and the threshold at high

with this adjustment, the depth of detection drops a lot

every pot is related to the depth. you certainly must set pulse width on maximum, but can not, because
you have:
- limited power reserve of battery
- influence of miniralized ground.
you must seek OPTIMAL FOR YOU SETTINGS.

second example, first delay width. you get maximum depth with LOW delay, but then DP sees every nails.
again, you have to find out OPTIMAL SETTINGS.

also with second delay width (GEB). at right position you get maximum depth but on miniralised ground
you must set it at left and you lose the depth.

you see - you must find out OPTIMAL SETTINGS FOR EVERY CONDITION OF GROUND YOU ARE SEEKING ON
GETTING MAX DEPTH CLIPPING OUT NAILS.

[ramin]

hi anatolij

I made dp and it's a perfect metal detector

Now I made a 110*110 cm coil without shield for Dp and it works very well

But i made another one, I used a shielded cable i connected the two end of shield

but when i test the dp with this I had to adjust the first delay width at high point and the main pulse width at low point and the threshold at high

with this adjustment, the depth of detection drops a lot

[gaby_sult]

Vadim 18 .... This scheme I made myself, check the values and I assure you that you will have the highest performance.
Have a nice day.

[Vadim18]

Books are not to blame if the head is empty

Dear SWL, i only want to say i didn't have other information until i got acces to internet in 2008.
Regards.

[kt315]

try to load all DP files https://dfiles.ru/files/yi7t9r92k?redirect
yes, i do not do a secret from my archive. you have to see 'full doc set'.

[SWL]

let all them burn in hell

Books are not to blame if the head is empty

[Vadim18]

Mr. kt315 I only analysed schematic Sniffer_XR-71_sch.pdf which was new for me, and "trying to see " as was writen in the post #3693


If i had this schematic in 2002, or MD pirat at least... I soldering as hobbyst already ~25 years (from 7years), but all circuits i have was only soviet books about audio and radio, radio and audio until 2008, let all them burn in hell... My closest to pi detectors circuit was Chemelec battery desulfator in 2015, then was SurfPI, last year Clone PI-W and Delta.
Offcourse if i don't understand circuitry for at least by 50% - i don't build it.


Yours respectfully.

[kt315]

Vladimir (Demchenko) did draw this schematic, but he took the value from DP. in original schematic of Gueorgui 'mustang' (nick)
you see 1k. BTW Mustang hard promised to send me his board, but never did fulfill a promise.
you can write to Mustang with your calculation of current (mistake #2).

from: Gueorgui Gueorguiev <[email protected]>
subject: XR71

Hello KT315,
I/m can send you a pcb which is tuned and work well. Do you interest of it?
Gueorgui Gueorguiev
[email protected]


We haven't to speak for price. I'll send pcb not for money but for something similar. Last year I sent to Jurij some coil shells - you can ask him. My XR71 pcb is the same as "Aban" sent in Carl forum. He ("Aban" is pseudonim which one bulgarian boy have used. He is from Burgas and is very good liar.) He had stolen my pcb at the early 2000. This pcb have manifactured yet have a bit modification - we added a part with batery changer and lowbat indication. As you good know on pcb are switch for "Manual" - "Auto" tune which was soldered in "Auto" mode in "Aban" pcb. The main advantage my pcb is spetial selection for IC and pasive - You mast know this is "secret", because there were many XR71 detectors were manifactured but when you will test any from "VE EL electronics" you could register adventage. I have many detectors and think it was one of the best models at the time and can compare it.
About XR71 I can say that it "Father" XR7 (I had manifactured 3 devices before XR71) was one very fine designed Pi machine. If you are interesting I can send you shematics of XR7.
Best regards,
Gueorgui Gueorguiev