Delta Pulse

[porkluvr]

The problem is when i turn noise pot over the first half of the whole turn for better detection the red led also brightens up and detector just beeps once then gets silent and stops detecting and irf740 starts warming, so when i turn the noise to lower again it starts working normally.
Also one more thing that may be important the 9v1 zener gives me 8.85v when working normally and 8.2 when this problem occurs.

Your "noise" pot can be more descriptively called the Pulse Width (PW) pot.

The Red LED's normal function is to illuminates when your battery is weak, needing recharged.

But also, for any transmitted PPS (Pulses Per Second) setting, there will be some value of PW that will cause current consumption to exceed the battery's current delivering capacity. When that happens, the battery voltages drops, and the red LED will illuminate. That is telling you to reduce either PPS or PW, reducing battery consumption to a more reasonable value. Or, you could instead decide to live dangerously, and use a bigger battery... but in the case of your FET getting hot that is not a good idea.

If you have a milliammeter, connect it in series with your DP and the battery. Watch what happens as you change the PPS and PW controls. I have read that a reasonable maximum value of battery current to prevent the FET damage is somewhere around 150mA.

If you want to be able to have 100% usable range on your PW pot and you know the maximum PPS that you will ever use, you could set maximum PPS, and then modify the value of the PW pot to eliminate your unusable zone. Reducing the value of PW pot (or paralleling a fixed resistor across the pot) will reduce the maximum pulse-width. But you must first determine maximum desired PPS.

If you want to keep the full range of PPS but also keep the full range of PW, then you will simply have to accept the fact that you cannot use maximum PW and maximum PPS at the same time.

Increasing the value of PPS pot (or R1) reduces maximum PPS frequency.
Decreasing the value of PW pot (or C3) reduces maximum Pulse Width.

[alonejax]

thanks purklovr
my battery is 12v 4a dry battery
when i start give me 4.12Amper and my irfp460 is hot, is normaly?
i dont think my battery low
thanks alot

[porkluvr]

thanks purklovr
my battery is 12v 4a dry battery
when i start give me 4.12Amper and my irfp460 is hot, is normaly?
i dont think my battery low
thanks alot

You'd better disconnect the FET from 12V drain power and make sure your 556 is working properly. Removing the coil should be sufficient.

Your current draw should then reduce to about 5~10mA (just a guess).

Place your multimeter lead on ground, then you should measure about -6V on 556-5 and 556-9. Those pins' voltages should increase slightly as you rotate each's associated potentiometer clockwise. (PPS changes 556-5 voltage, and PW changes 556-9 voltage).

If you have a frequency meter, you may be able to see frequency changing on 556-5 and 556-9 as you rotate the PPS pot. These two pins' signal duty cycle may be too low for reliable triggering on your F-meter, but try it anyway.

[alonejax]

hi purklovr
i will check it, thank you
do you have information for minelab or one detector sence only gold ?

[hadi-dindar]

hi friends

can any one help to to make a coil for deltapulse3 ?

i have only 0.5 Copper cable.

[alonejax]

hi hadi
mokhlese hameye ironiha!
vase coil az hodode 30 dor sim 0.35 be shoae 19cm estefade kon
ohmesh hodode 3.4 mishe ke ba movazi kardane ye moghavemat 2.2 ohm 1wat mizon mishe
Good lock!
[email protected]

[alonejax]

hi purklovr

thanks for your attenation my friend
i remove my coil and check my amper is 5ma! its normaly
but in my 556-5&9 i only have 1.7V
means my 556 is fail?

[porkluvr]

thanks for your attenation my friend
i remove my coil and check my amper is 5ma! its normaly
but in my 556-5&9 i only have 1.7V
means my 556 is fail?

Possibly. But first, what do you measure to pins 7 and 14 on your 556? (Those are the the power input pins.) Be sure to put the (-) meter lead at the same place, every time you make voltage measurement.

[alonejax]

ok
i check betwen pin 7 and 14 is -10.76 volt
but between pin7and negative battery plat is 1.76v
pin 14 and negative battery plat is too 1.76v
i check pin 6&5 again
betwen pin5 &6 is -5v
and betwen pin6 and -battery is 1.7
pin5 and - battery is too 1.7
only when i connect coil , noise volume can up input amper! its normaly?
i have betwen pr1 and negative battery plat 1.64v
and betwen pr1 and positive battery plat (-10.6)

[kt315]

PLEASE do not overload me by your private messages with your Delta Pulse's problems' requests. I am answering HERE AND ONLY HERE. in case if you repeat Turkish design so ask Turkish people, NOT ME.

good luck

[porkluvr]

ok
i check betwen pin 7 and 14 is -10.76 volt
but between pin7and negative battery plat is 1.76v
pin 14 and negative battery plat is too 1.76v
i check pin 6&5 again
betwen pin5 &6 is -5v
and betwen pin6 and -battery is 1.7
pin5 and - battery is too 1.7
only when i connect coil , noise volume can up input amper! its normaly?
i have betwen pr1 and negative battery plat 1.64v
and betwen pr1 and positive battery plat (-10.6)

If you measure 10.76V across pins 7 and 14, that is OK. But that would mean it is impossible to measure from battery (-) and have 1.76V to both 7 and 14, unless you made a mistake.

Please show me where to find the exact PCB layout and the exact schematic you are working from.

[porkluvr]

only when i connect coil , noise volume can up input amper! its normaly?

Yes that would be normal, but your information is not complete.
What current do you measure when the noise pot is turned fully counter-clockwise (with coil installed)? Then, what do you measure with noise pot turned halfway?

[Orbit]

Given to someone for the English version hex code lcd display ? just come for the Turkish version only partially !

[maximusdesmus]

Thank you porkluvr for your repply ,the problem was acctually simple or if we could call it a problem the mosfet itself starts heating when coil resistance is below 2.5ohms,since the last post i have built a few nice coils with 0.53 enameled whire and they work just fine with resistances from 4 to 5.5ohms,i will measure the miliamprerage and try to be around 150mA as you said,for now i have made some small changes inducing higher sensitivity for smaller objects ,which exactly is what i will use this machine for,i dont like digging big holes
I have also tried constructing copper shielding around the board and it does perform more stable as far as ground sensitivity but dp s stable by itself well enough so it does not make a big difference,idealy a faraday cage should be placed around the oscillating unit but theres not big need for that,althou i say again it does perform more stale.

Im transfering the pcb design into smd and ill post finished dp and results when im done.
So far so good,its a nice machine but a DEEPER so all of you that will build one know that for all around detecting and coin hunting this is not a fine choice,im taking my caesar and goin some huntin tommrow hah,greetings to all ppl on geo from Serbia.

Orbit,pm me on hobi.

[alonejax]

thanks friend
my pcb is on page: http://www.geotech1.com/forums/showt...a-Pulse/page82
if you want video for the true delta i can upload.
my delta work but is poor
thats sens a box 12*5cm in 7cm in air
i think my coil isnt good,i change some part for better sens gold and small object
friend please help me..