Delta Pulse

[Manu]

Hi everybody,

I have just finished to build the Delta Pulse metal detector and i would like to compare their performances with you. With a head of 20cm diameter and 30 loops of 0.5mm wire, i detect a can of coke at around 45cm. I think it's a litle bit short and it's why i ask you how deep you obtain.

Best regards

Manu

[Willy Bayot]

Re: Delta Pulse

Do you really SEARCH for cans of Coke?
You should not use this as a reference for depth measurements. Use for instance various Euro and/or US coins, they will be much more acceptable as comparison marks.
However, 45 cm for such a can is QUITE short, specially in the air.

Willy

[KT315]

can anyone say

I found/see first mention on Delta Pulse in the forum, Eugenij did share the shematic. I wrote him, but his address is unaccessable/not existing.
maybe anyone have also schematic in a format of CAD software? I would be happy to this.

regards

[Alexis]

Re: Delta Pulse

Hello manu,
Your detection of a can of coke is very low , normally you will detect it at 70cm , 75 cm and with better circuit at 80-85cm.
Note : the can of coke in America is make of aluminium and in Europe in general in steel !!!!
You must check your coil inductance 350 to 400 uH with a low resistance Ex: 3 to 8 Ohms.
Do not desesperate check ,the circuit block to block ,you will find why and also learn more about it.
Have a nice day, Alexis.
and yes for me it is a good reference coke can because all around the world you can access it .

[Manu]

Thank you Willy ans Alexis

Hello Willy and Alexis,

Thank you both for your answers. No, i'm not use to search cans of coke but for me is a good reference for medium objects. And money depends of the country where you are. But for example with euros i obtain :

5 cents ==> 19 cm
10 cents ==> 17 cm
50 cents ==> 21 cm
2 €uros ==> 20 cm

For make the coil, i have use the following formula of inductance for flat coil :

L = (µ0 x N² x S) / (2 x R)

Wich one become

L = (µ0 x N² x p x R) / 2 for round coils

That give an inductance of ~178 µH and a resistance of ~3 Ohms for a diameter of 20cm (a ray of 0,1m in formula) and 30 turns. So if the inductance should be 350 or 400 µH the problem must come from the coil.

If i reverse the same formula for obtain the number of turns that give me an inductance of 350 µH and 400 µH it gives me respectively 42 turns and 45 turns. Unfortunatly i don't know how to mesure inductance, it's why i use calculation

Please tell what are you thinking about thoses results and it seems you correct. By my side, i continu to check all components.

Best regards

Manu

[Manu]

Question about condensators markage

Hello,

After have checked and re-checked my components, i have a doubt about the markage of condensators.

On the DP MD plans there is C13 = 15 pF and C17 = 47 pF

And the condensators i had received are marked like this :

+ 150 HQ J
+ 470 AQ J

I know there is ambiguity between two norms of markage, the first who says :

+ That the last digit means the number of zeros to add to others digits for obtain a capacity in nF (XYN ==> XY + N zeros in pF)

In that case "150 HQ J" means 15 nF

And the second one who says :

+ That the capacity is just clearly written

In that case "150 HQ J" means 150 nF

But there is an ambiguity between those two norms (grrrrhhh!!! why is not clear .

Is anyone know if there is a priority to apply the rules ? As you guest i'm novice but i'm still arrived to build it and it was fun but right now is just a shame to be annoying by that

I hope my problem is just that !!!!

Best regards

[Manu]

Re: can anyone say

Hi KT315,

Schematics of DP are on this forum in a message of Jean Charles Morin, the author of those one but not in CAD format. In searching a little bit you will find.

Best regards

[KT315]

Re: can anyone say

OK. I have it. I am interesting in CAD format of schematic and PCB. I would like to modify the PCB. Withal graphic format is not usefull for order on a firm.

anyway thank you.

[Manu]

Re: can anyone say

Yes i anderstand but i don't have it. However if you build it, don't hesitate to communicate your performances.

Good luck

[Alexis]

Re: Delta Pulse




Hello Manu ,
For the coil :
Diameter= 28 cm (11inch the best compromise rapport)
- 19 TURNS Wire caliber= 25 Awg (0.45mm)
Resistance = 2 Ohms ; Inductance only the coil =335 uH measured .
A good Dynamic searchcoil.
Have a good construction , Alexis.

[geo]

Re: Delta Pulse

Witch is the sensitivity for 2euro and for 330 ml can with this 11in coil?
By the way very nice coil.
Geo

[Manu]

Re: Delta Pulse

Hello Alexis,

What a beautyfull realisation ! My coil was made by assembly of three disks of plastic but it's so nice with a circular tube. However i have never anderstood how can the coil enter in a circular tube without cutting the tube ? It's a real interogation. You may be turn the wire in the unclosed tube, after what you make the coil turn in the tube for bring the wire closer together with tape or something like that ? After what you connect your cable to the coil and close the tube ?

Nice realisation again ! I will try to make one similar. Do you use it with Delta Pulse or an another detector ?

Wich performances do you obtain ?

Thank you very much, Manu.

[Alexis]

Re: Delta Pulse

Hello Manu ,
Yes , first you make the form of the coil with pvc water tube with hot gun (the tube is filling with sand for make and put in a wood form ) after you put the wire turn after turn with a piece of flexible steal wire (like a giant needle) for 19 turns it take me 15 minutes not soo long, what you need is space!!! after you fill the tube with peanuts packing form (the wires must be firm in the tube ,not shaking), well condensed, and after you solder the wire and coaxial , isolate with paper masking tape (the best) and fix it with epoxy glue it is very important NOT to use silicon compend because it generate a corrosive vapor bad for your connexion .After you compress the coil a little and glue the end of the tube with the T Ok,I hope it is clear!!!
have a good day,Alexis

[Alexis]

Re: Delta Pulse

Hello Geo ,
For the can like i said :
70 to 75 cm and with a best design circuit 80 to 85 cm Treshold, in a moderate soil you will detect it at 70cm and 80 cm for sure.

[Beachcomber]

Re: Delta Pulse

Is your coil shielded? If so how were you able to shield it? It looks very nice!!! Excellent workmanship!!!

HH

Beachcomber