Surf PI Pro

[bernte_one]

pinpointer?

hello

is it possible to add a pinpointer wiring according like surf pi (normal version)



@smaeel
try to use i cable with bigger diameter 0,5mm+, litz or monocore wire (to lower the resistance for more power)
with insulation (the insulation at the enamled copper wire is to thin)
do not bundle the cable too tight let some fresh air between the cables
the coil can better breath äh i mean charge/ discharge - so faster pulses and better performance are possible

regards

[smaeel]

Hi Jim
Thank you again.
It seems the board is highly dependent on the coil.
I build a coil with these properties:

D(coil diameter):22 cm
n(number of turns):20
d(wire diameter):0.3 mm
L(coil inductance):260 uH
R(coil resistance):3 R

It works
A 25mm coin is detected from 19cm in the air.
There is no sensitivity to gold.

My setting up procedure :
I started by zero the 5534 using offset pot. and then using threshold pot. to get maximum depth.
The delay pot. causes disconnecting beep when turns.
The gain pot. causes some background noise when turns.

Other coils with bigger inductance not work at all in my test.

I'll be very grateful if someone helps me for exact setting up procedure and the operation of the "delay" and "gain" potentiometers.(I have no oscilloscope)

Thanks for your kind attention.

Regards
Smaeel

[Sean_Goddard]

Can I throw a suggestion or three in here?

Drop the noisy 7660 beef up the supply lines and add regulators (7805 and 7905 or the like and use THIS http://www.datasheetcatalog.org/data...ts/tle2426.pdf).

See how the noise figures drop then try moving gain values around the circuit. What I mean by this is say front end currently had X1000, try 100, 200, 250 or some other value. Make the gain up elsewhere in the circuit.

Remember the recovery speed from overload (bandwidth too) is a factor of GAIN so maybe not quite so much at the front end eh?

Try using metal film resistorsthroughout too, and don't forget that resistor noise is a function of value, so keep ALL resistor values as low as possible

[TH Jim]

Hi Smaeel,

Very nice looking board you have made! It is necessary to connect the coil in order to set up the detector. Try setting the pots to half way and tweak them from there to improve performance.

@ Bernt_one

Hi Bernd,

Try looking at the output from the 4066 of the first sample, then adjust the offset and notice the changes to the sample. You should be able to figure it out from there

Cheers all,

Jim.

[bernte_one]

hello davor

you can extract a list of materials from the eagle files posted by thjim

or you take them from the picture of the component side and make a notice by yourself

for every part you wrote to your list make a mark on the picture to make sure you count not a part two times

regards

[Davor]

Funny I didn't find a complete bill of material

I also wander if using a somewhat faster mosfet, such as IRF6220 with lower Coss would do any better here. Guess it would require somewhat larger damping resistor.

There is a slight possibility that I'll take on this one once my IGSL is done. With some changes, of course.

[smaeel]

My "surf pi pro" not work

Hi to every "surf pi pro" freinds of Geotech forum.
I want to thank Mr. "TH Jim" providing this beautiful schematic and pcb in Eagle.
I constructed my project based on this post of Mr. Jim :

http://174.132.129.189/~moreland/forums/showpost.php?p=144808&postcount=32

Although making it very carefully , nice installing and soldering (I think) , but it is not work.
There is no sound in any position of all potentiometer,with or without connecting coil.

There is +5v at output of regulator.
There is -3.68v at pin 5 of ICL7660.Is it correct?
The regulator starts warming.
There is about 40 mA current from my power supply connected to devise.
The IRF9640 and 390R not warm at all and I think the mosfet not started and not sending any current to coil.
Only at start connecting 12v DC voltage to devise I heard a 0.5 second beep and it disconnected immidiately.
Can someone please help me setting up devise from connecting voltage and changing any potentiometer to have some beep.
Is the coil connecting is necessary for this procedure?

thanks for your help
regards
Smaeel

[bernte_one]

surf pi pro setup procedure

hello to all here

i need some intsruction for setting up my surf pi right

volume, gain and threshold are not the problem.
but where can i check if offset is right adjusted
or how should it be adjusted (measured output of which ic?)

delay i set so to get good performance and i have a little area to control it with the potentiometer

but offset is more critical

so thanks for your answers

[yhl]

1

11

[yhl]

Cable

I have produced success.The detector can distinguish between the cap / aluminum foil and cans pull ring.Twisted-pair coil is very sensitive.I use three mobile phone battery / 3. 7V1300MAH ./11.4V

[TH Jim]

@Yhl

Thanks for the link to the very interesting coil info

I also see there are a lot of guys building the SP Pro on the forum

http://vrtp.ru/index.php?showtopic=19745&st=120

It's nice to see my PCB has gone global!!!

Cheers, Jim.

[ONoff]

PCB SMD?

Who has PCB SMD? Please give.
Thanks!

[yhl]

Good technical forum

Good technical forum http://vrtp.ru/index.php?showtopic=19745&st=120

[yhl]

Use three mobile phone battery power.3 7V series.

Use three mobile phone battery power.3 7V series.

[yhl]

Give a link / coil will increase the distance of 20%.

Give a link / coil will increase the distance of 20%.
Need Google Translate

http://www.metdet.ru/korsina2.htm