MINIDIVER (minipuls+minediver)

[sisco]

Geo , can tell me find these clocking by calculate or osciloscope?

my tiny clocking is calculated (not see in OSC).

see this picture , if 4538 datasheet is true my calculated must true.

1set Delay =>R1 X C1 => (SIGNAL pot + R7) x C1 =225us - 975us

1 sample width =>R2 X C2 => 40us

interdelay =>R3 X C3 => (SENS pot + R9) x C3 = 1ms - 8.5ms

I test my minipuls with digital OSC and saw , yes Max your answer is true :

minipulse 1set delay was 7us (infact 6.9us).

[sisco]

Max , interdelay must 200us distance with ending of 1sample delay ,true ?

[Geo]

Geo , can tell me find these clocking by calculate or osciloscope?

my tiny clocking is calculated (not see in OSC).

see this picture , if 4538 datasheet is true my calculated must true.

1set Delay =>R1 X C1 => (SIGNAL pot + R7) x C1 =225us - 975us

1 sample width =>R2 X C2 => 40us

interdelay =>R3 X C3 => (SENS pot + R9) x C3 = 1ms - 8.5ms

I test my minipuls with digital OSC and saw , yes Max your answer is true :

minipulse 1set delay was 7us (infact 6.9us).

Hi Sisco .
I measured the times with Oscilloscope.
I have one original DP and other 2 made by me. All have the same clocking.
But if i remember OK potentiometer SENS is 220K at my Detector.

[sisco]

Hi Geo , I true understand ?

[sisco]

Hi Sisco .
I measured the times with Oscilloscope.
I have one original DP and other 2 made by me. All have the same clocking.
But if i remember OK potentiometer SENS is 220K at my Detector.

220k not problem, bicause in minimun time (only R9) interdelay must 1ms not

120us??

are you sure don't change R9 , C6 , R7 , C4 ?

because in delay width my calculated like you (40us ~ 45us) ?

[Geo]

Hi Sisco .
Of course i am sure. I have not changed anything.
But at your schematic out1 must be 15us after the "IN pulse" fall
I attach the clocking of my DP
Regards

[sisco]

Ok Geo ,

I write this program , start first delay after "IN pulse" fall.

see and tell me this is true?

[sisco]

I have a better idea , why must use NE555 for make pulse , can use micro

for do this .

Max, see this schematic and if this is true tell me , I have make it and test

your idea about timing.

If don't work.....

[Geo]

I have a better idea , why must use NE555 for make pulse , can use micro

for do this .

Max, see this schematic and if this is true tell me , I have make it and test

your idea about timing.

If don't work.....

It seems OK
Good Luck

[Max]

I have a better idea , why must use NE555 for make pulse , can use micro

for do this .

Max, see this schematic and if this is true tell me , I have make it and test

your idea about timing.

If don't work.....

Hi,
you have to put a differential integrator between sampler and audio stage.

Look at hammerhead pdf for more details about that.

Kind regards,
Max

[nelson]

Hi Sisco and congratulatins for this beautifull MD you have done.
I m still working with my Tesoro Golden Sabre, but after that i ll try a few more projects and this one looks very promising, so i started to collect information about construction.
So, for that can you send me the PCB file?

In advance many thanks
Nelson

Hi all ,

Finally, ready my new project ,

first , I can't find tel-12... part so use two battery but if you can find this

part not need two battery.

second, you can see original minediver in this address:

http://www.pulsdetektor.de/projekte/projektindex.html

I am busy and very tired, so test this metal detector for 4-5 time but

understand :

abut sensibility , with very good adjust with 35cm coil can detect

50cm X 50cm at 2m. (I only can do this for two time because can't adjust

very good in home).

with 35cm coil detect small silver ring at 19cm

and for other test like small coil , gold (because this metal detector have

DELAY adjustment) must wait, because my battery under charge.

If somebody have PCB layout tell , I send .

be successful

[sisco]

Hi nelson

first must tell , this metal detector very good for deep and finding small

object but have a problem , not sensitive to gold.

I try to find way (with change delays) for this problem.

this is PCB layout for minidiver.

[sisco]

Max , your idea about timing , I want first make new device for test your

idea but think and decide first test this timing on my minipuls.

so erase minipuls ATMEGA8 and programmed by new program (1KHz ,100us

PW ,15us , 45us first delay , 200us interdelay and 45us second delay) and

test , what you think ?

YES this work and I can detect GOLD with this timing.

this is my programm writed on ATMEAG8.

evrey step =3.75us for example A = 27 mean this time is 101.25 us (IN THIS TIME MOS-FET IS ON)

$regfile = "m8def.dat"
$crystal = 8000000
Config Timer1 = Timer , Prescale = 1
Stop Timer1
Config Portb = Output
Config Portd = Output
Portb.1 = 0
Portd.6 = 0
Portd.7 = 0
Dim A As Word

Startline1:
Start Timer1
A = 0
Portb.1 = 1
Do
A = A + 1
Loop Until A = 27
Portb.1 = 0
A = 0
Do
A = A + 1
Loop Until A = 4
A = 0
Portd.6 = 1
Do
A = A + 1
Loop Until A = 12
A = 0
Portd.6 = 0
Do
A = A + 1
Loop Until A = 53
A = 0
Portd.7 = 1
Do
A = A + 1
Loop Until A = 12
A = 0
Portd.7 = 0
Do
A = A + 1
Loop Until A = 158
Stop Timer1
Goto Startline1


TIMING:
Frequncy = 1001.5 Hz
PW(ON PULSE) = 101.25us
delay= 15us
first delay = 45us
interdelay = 198.75us
second delay = 45us
OFF PULSE = 592.5us

FOR 1000HZ:ON Pulse is 100us so OFF pulse must 900us calculate = (15us+45us+198.75us+45us)-900us =~595us

[Max]

Max , your idea about timing , I want first make new device for test your

idea but think and decide first test this timing on my minipuls.

so erase minipuls ATMEGA8 and programmed by new program (1KHz ,100us

PW ,15us , 45us first delay , 200us interdelay and 45us second delay) and

test , what you think ?

YES this work and I can detect GOLD with this timing.

this is my programm writed on ATMEAG8.

evrey step =3.75us for example A = 27 mean this time is 101.25 us (IN THIS TIME MOS-FET IS ON)

$regfile = "m8def.dat"
$crystal = 8000000
Config Timer1 = Timer , Prescale = 1
Stop Timer1
Config Portb = Output
Config Portd = Output
Portb.1 = 0
Portd.6 = 0
Portd.7 = 0
Dim A As Word

Startline1:
Start Timer1
A = 0
Portb.1 = 1
Do
A = A + 1
Loop Until A = 27
Portb.1 = 0
A = 0
Do
A = A + 1
Loop Until A = 4
A = 0
Portd.6 = 1
Do
A = A + 1
Loop Until A = 12
A = 0
Portd.6 = 0
Do
A = A + 1
Loop Until A = 53
A = 0
Portd.7 = 1
Do
A = A + 1
Loop Until A = 12
A = 0
Portd.7 = 0
Do
A = A + 1
Loop Until A = 158
Stop Timer1
Goto Startline1


TIMING:
Frequncy = 1001.5 Hz
PW(ON PULSE) = 101.25us
delay= 15us
first delay = 45us
interdelay = 198.75us
second delay = 45us
OFF PULSE = 592.5us

FOR 1000HZ:ON Pulse is 100us so OFF pulse must 900us calculate = (15us+45us+198.75us+45us)-900us =~595us

Hi,
Well done.
Now test if it gives false signals or not if you can.

Kind regards,
Max

[sisco]

HOW?