delta pulse more sensitive to gold delay reduced

[ossamaussama]

Hello Ossama and Jose

I have built 2 units but in both cases i don"t get really good stability and depth.Probably i made them with no oscoloscope...and meaby i am testing them inside the house with lots of powerlines.
I"ve got confused from seen so many schematics and versions of this unit. Some have the high speed diode..some dont have it...the specifications were not clear for the precision electronic parts and key elements on circuit.
I was wonderig for a wile now ..and since i am not an expert this though keeps on coming..can we ad to Delta Pulse a VISUAL TARGET ANALIZER? such a small mini osciloscope where we can decide wich type of metal is under the coil by reading the curve on the osciloscope display? Is that hard to make?
I think that Delta Pulse can be a lot better ...
Also having a new revised parts optimised for large coil use and also the set-up for small coil... I am thinking to take to a separate pcb R5,R6, R1 etc... and use a swich for best setup on 1x1 and smaller 20 cm coil...wont be that a better choice to use DP for small and large objects with the help of a swich?

Thanx
Regards
Marius

stability need good coil for 28 cm u use 28--35 turns with resistance 2 to 3 ohms

good battery to ensure stable voltage


for small coil 300 hz give good stability

use high gain the device will not b stable

c32 is important with R50

4700Uf OR higher is better



delta pulse should detect 1 euro in 32 cm or more easily even underground tested many times

large coil cannot operator with low delay keep that in your mind

dumping resistor for large coil is in range 680-----800 ohms

for small coil 1000 ohms to 1400 ohms

i use 1.5 k ohm in my device and i use 2k in parallel with the coil so when i connect the large coil

the dumping will be 1.5*2/3.5= 850

more tx power also affect stability noise .....

the second delay p2 affect on stability


R6 better to be fixed 1k up to 1.5k as jose said it affect in stability in nice way




inside hose there is alot of noise test it outside or try change the frequency

[Jose]

Hello Steaua581
The stability of the DP depends on many factors, some were described in the previous post,.
Ossumaussama, also described some changes.
Tadas are personal experiences that gave results that try to describe here in the forum.
In my case the change of R6, the addition of fast diode, the properly adjusted buffer R5, with a balanced coil, etc., were successful.
A good PCB, also influences stability. I realized bridges on the lines of +E,-E, and midpoint of the tension to decrease the resistance of the tracks, and improved stability.
Also short connections and grounding (+E) of the connector of the coil and the metal parts of the potentiometers, can improve stability.
The tests can confuse autamatico mode, not knowing if abanzamos or backwards.
The tests I performed in manual mode in this way (see my scheme published in the previous post).
Place in manual mode.
Adjust the gain at its midpoint.
Adjust the threshold, at its midpoint.
Set 125 to 150useg power.
Fit range 200 to 300 usec.
Reduce the delay until the start clicks on the speaker.
Fine-tune the threshold so that it is regulating a 2 or 3 clicks per second.
I think the test in manual mode, lets us know whether or not improved with the changes we made.
I also plan to use a handheld oscilloscope to see the curve of the different metals. Do not know if it works.
Below is a plan to address discrimination for the DP.
regards


http://www.teknolojiekibi.com/

[pigeon]

hello

is what you can? give me the exact changes to use a coil of 1 meter? is what I have to change to have a good stability of the detector and a maximum depth.

I beg you to please help me

thank you very much

[pigeon]

HI

I USED IRF460

[Jose]

hello

is what you can? give me the exact changes to use a coil of 1 meter? is what I have to change to have a good stability of the detector and a maximum depth.

I beg you to please help me

thank you very much

1x1 meter coil
In the original design, I use 18 laps.
With the suggested changes, I use 12 turns.
Adjust R5 in both cases.
regards

[pigeon]

hi
I'm using 680 ohm for résistance5

I use the ADSL cable to the coils 1M aand 50CM but my delta is not stable what should I do to fix it

best regards

Pigeon: (

[ossamaussama]

hi
I'm using 680 ohm for résistance5

I use the ADSL cable to the coils 1M aand 50CM but my delta is not stable what should I do to fix it

best regards

Pigeon: (

what is the coil resistance?

should be in range 2--4 ohm

try reduce the tx power

reduce the gain

or use 1k instead of 680

try increase the delay little

what is the health of battery voltage during turn on

because some battery read 12.3 and when you turn on the device it will go down to 11

this is because of high internal impedance and this is bad for stability


check that

check if there is error in connections

and at last when testing 1M coil it should be

1- far away from electrical interface

2- above the ground about 15 cm



regards

[pigeon]

hi



I use a resistor in series depending on the size of the coil

is what I have to change the 680ohm?



thank you

[ossamaussama]

change 680 to 1k

what is the dumping used in both coil?


R5

higher value will make instability

for me

i use fixed 800 ohms in 28cm coil and in 1 meter coil

[pigeon]

hi

The two coils can detect up to what distance?

is that you use a series resistor for the coil 28cm?


thank you very much

[ossamaussama]

hi

The two coils can detect up to what distance?

is that you use a series resistor for the coil 28cm?


thank you very much

28 cm coil with 25 turns and resistance 2.5


large coil 1m 16 turns and 3.8 ohms

detection

for 28 cm coil

1 euro detect about 33 cm or little more

coca can detected 70 to 74 cm

air test


for large coil i use low frequency

coca cola can 330m detected 1.6 meter air test

under ground it depend on ground conditions


note: some one try to use 40 turns for 25 cm coil and they say it give better results




regards

[pigeon]

hi


is what I use the ADSL cable if not what is the diameter of the wire should I use?

the coils must be square or circle?


how I can make the adjustment of the potentiometer?


thank you very much

P.

[Jose]

Hello Paloma
The cable is generally used RG 58. The same equipment used in VHF mobile
The coils can be square or round, some say the round is better.
I use redendo Roll 28 cm. Square 45 x 45 cm.
For each roll you make, you should experiment with the damping resistor (R5), each case is different
Perform the test in manual mode.
If you get a good stability and sensitivity in manual mode, auto mode will work better.
regards

[pigeon]

hi


thank you

[steaua581]

stability need good coil for 28 cm u use 28--35 turns with resistance 2 to 3 ohms

good battery to ensure stable voltage


for small coil 300 hz give good stability

use high gain the device will not b stable

c32 is important with R50

4700Uf OR higher is better



delta pulse should detect 1 euro in 32 cm or more easily even underground tested many times

large coil cannot operator with low delay keep that in your mind

dumping resistor for large coil is in range 680-----800 ohms

for small coil 1000 ohms to 1400 ohms

i use 1.5 k ohm in my device and i use 2k in parallel with the coil so when i connect the large coil

the dumping will be 1.5*2/3.5= 850

more tx power also affect stability noise .....

the second delay p2 affect on stability


R6 better to be fixed 1k up to 1.5k as jose said it affect in stability in nice way




inside hose there is alot of noise test it outside or try change the frequency

Hello Ossama and Jose,

I finally found my problem. I have built Delta Pulse 2 Elbobaci design. After palyng around with many IC versions i found great stability from using HCF4066. The sound clicking from DP is verry nice and clean. Also the detection with 40 Cm coil is great. I can detect a bit biger helmet size target at 1,40 cm in the air. Coke of can 80 cm. Euro coin at 25 cm.Looks like is great for bigger objects. I did not play much with the settings.
I have built two coils of 1x1m.One of 12 turns and one of 16 turns using ADSL cable.
I am still looking for best sensitivity on using large coils.

Ossama and Jose ..you sugest on attaching a paralel 800 ohm resistor for each coil? What would be the R1,R5 and R6 in that case? I have R1 of 680k. Is that ok ?

Thanks for great help
Marius