IF YOU HAVE MAKE , TRY THIS .

[Max]

Hi,
I think that is first delay the big problem.
If it's 150uS for sure have problems detecting gold... and also other things.

Good for depth search of iron or also copper alloy, brass but for big objects only.

Solution could be modifing it to stay from 10uS to 20uS as first delay, but also coil shield become important at and under 15uS first delay.


Best regards,
Max

[Geo]

Hi,
I think that is first delay the big problem.
If it's 150uS for sure have problems detecting gold... and also other things.

Good for depth search of iron or also copper alloy, brass but for big objects only.

Solution could be modifing it to stay from 10uS to 20uS as first delay, but also coil shield become important at and under 15uS first delay.


Best regards,
Max

Hi Max.
Yes the problem is sure the 1st delay. A good choice also is to use 30us so he will have a medium to good depth for the gold and coil without shield. 5 or 10us is better but he must use a good quality wire so the total capacitance must be low and the tune of the coil hight. The choice is from Sisco
Regards

Btw .. 150us is special delay to reject small golden objects ha.. .. ha

[sisco]

I think not bad for detect small object because i detect with this one small

coin at 32cm .

I dont know where must test delay pulse .

for delay I test in pin13 Atmega8 .

I adjust all potentiometer but this signall fix in this location and

don't moved.

Is this delay signall?

(This metaldetector work fix 500Hz)

[Max]

I think not bad for detect small object because i detect with this one small

coin at 32cm .

I dont know where must test delay pulse .

for delay I test in pin13 Atmega8 .

I adjust all potentiometer but this signall fix in this location and

don't moved.

Is this delay signall?

(This metaldetector work fix 500Hz)

Hi Sisco,
don't understand your diagram.

First delay start from main pulse (tx) switch-off ahead. I read that this detector (on pulsdetektor website) have 150uS first delay ... so you have to see a 150uS pulse (positive or negative) that start just at tx switch-off.

Then after 1st delay pulse you have to see "first sample window", another pulse that goes to sampling gates (usually from 15uS to 50uS of duty).

Best regards,
Max

[sisco]

maybe first delay adjust into atmega8 by software.

if you read minipule detail (on pulsdetektor website) can tell me RANGE

potentiometer for what ?

[Max]

maybe first delay adjust into atmega8 by software.

if you read minipule detail (on pulsdetektor website) can tell me RANGE

potentiometer for what ?

Hi Sisco,
I've not read all but just the spec. sheet on their website. I think that timing for first delay is set in atmega8 software.

Have you just .HEX file ? Not the assembly code ?

Cause if you have assembly code you could change it in software... then reprogramming the ATMEGA8.

Another solution (but ugly) could be disconnecting that pin and using a monostable (4538, 74121, 74123, 74HC121... ) to get right pulse duty (smaller than 150uS)... triggering the monostable with TX main pulse at gate of mosfet, like in detectors without MCU (atmega).

Kind regards,
Max

[sisco]

I have better idea .

only must wait for 5-6 days .if this work I can tell this metalldetector

better of all other metalldetector in this site .

(maybe barring GS4 and GOLDEN SABRE because i dont make these .

don'tworry .I make garry PI : not sensitive , Hammerhead : not deeper ,

deltapulse : don't work , sniffer (XR other deltapulse) : verry bad ,

Coinhawk : can detect big metal only at 5 ~ 15cm , so don't make other

metalldetector in this site.)

Max , what is your best metaldetector ?

[Max]

I have better idea .

only must wait for 5-6 days .if this work I can tell this metalldetector

better of all other metalldetector in this site .

(maybe barring GS4 and GOLDEN SABRE because i dont make these .

don'tworry .I make garry PI : not sensitive , Hammerhead : not deeper ,

deltapulse : don't work , sniffer (XR other deltapulse) : verry bad ,

Coinhawk : can detect big metal only at 5 ~ 15cm , so don't make other

metalldetector in this site.)

Max , what is your best metaldetector ?

Hi Sisco,
DeltaPulse works. XR-71 too. Are odd to make them work... sometimes, but if you find little mistakes and do few mods/tune they are ok.
Also others are not bad, but my best are:

PI: GS4 with 8'' round fast monocoil (but good only for beach, you know reasons)

VLF: BandidoII with DD22cm round coil

Now I've made GSabre and seems tunable even better than bandidoII.
But I think require some more time and a bit of mods.

If you need a good VLF (disc) -> GSabre, I found it stable and easy to do...
took me about 3 days total of work to get it working !
BandidoII took much more time... and performances are similar.

If you need a good PI I suggest still you make one of these (or find errors in yours already made):
DeltaPulse
XR-71
GS4

All good.
First 2 for depth search too 8I've modified timings), GS4 for small object search.

Kind regards,
Max

[sisco]

ONLY PI, I have problem with VLF , bicause good adjustment VLF coils is

really impossible (in finest adj).

about GS4 this is not good for me .you know why .

deltapulse : I make this like layout picture in this site but dont work.

[Max]

ONLY PI, I have problem with VLF , bicause good adjustment VLF coils is

really impossible (in finest adj).

about GS4 this is not good for me .you know why .

deltapulse : I make this like layout picture in this site but dont work.

Hi Sisco,
for sure it works. Ask Geo for PCB or even Ivconic they have/know everything about DP. I have all somewhere but can't remember which CD/DVD so it's a big task for me recover that stuff at now.

But it works and even well. And I think it's good for you.

Best regards,
Max

[sisco]

Max , I detect by my minipuls small coin at 32cm . can DP detect more this ?

If can ,what distance (you make this and must know)?

If DP is better , not problem for me , I make this for third time .

[Geo]

Max , I detect by my minipuls small coin at 32cm . can DP detect more this ?

If can ,what distance (you make this and must know)?

If DP is better , not problem for me , I make this for third time .

Hi. DeltaPulse work fine, but cant locate a small coin at 32cm because it is designed for small objects. If you want a detector for coins then your detector maybe it is the best (except the gold as you said).
Regards
......i will go for fishing for 2 days

[Max]

Hi,
as far as I remember it can detect (with mods. ) 1eur coin at 32-34 cm using 8'' round coil.
But you have to change many things, I mean timings. then it suffered from same behaviour of GS4 and others, cause of the smaller first delay (I've used 15uS). You know what I mean.
I find useful just VLF to avoid that problem. If you can make a good coil for e.g. GSabre as explained in GSabre thread you are fine with smaller objects search. Just use DISC mode and much false signals disappear.

Kind regards,
Max

[sisco]

Hi Max,

this is my new project (finally ready after 5 days), digital metal detector with
DELAY adjustment , I want test this tomorrow (must buy

microcontroller), if work good (I hope) send schematic for friends .

can I know anybody make minipuls or not ?

[sisco]

About battery charger ,

I see in one electronic website write: you must charge your battery under

1/10 battery current for 10 hour (not 12 hour) or under

1/20 battery current for 20 hour (not 24 hour).

for example my battery is 12V/2Ah so I must charge my battery under

200mA current for 10 hour or 100mA for 20 hour .

my RX for 200mA=> RX=>1230/200=6.15 ohm (for 10 hour) or

RX for 100mA=> RX=>1230/100=12.3 ohm (for 20 hour)

serial battery :

use 10 Ni-Cd battery 1.2V/700mA serial form : your total current is 700mA

and you must charge your batterys under 70mA current for 10 hour or

35mA for 20 hour.

parallel battery:

use 4 Ni-Ca battery 1.2V/700mA parallel form : your total current is 2800mA

and you must charge your batterys under 280mA current for 10 hour or

140mA for 20 hour .

be careful about battery because with little wrong damaged your battery for ever .(I do this for more 10 Ni-Ca battery)